Semiconductor device

ABSTRACT

An object is to realize high performance and low power consumption in a semiconductor device having an SOI structure. In addition, another object is to provide a semiconductor device having a high performance semiconductor element which is more highly integrated. A semiconductor device is such that a plurality of n-channel field-effect transistors and p-channel field-effect transistors are stacked with an interlayer insulating layer interposed therebetween over a substrate having an insulating surface. By controlling a distortion caused to a semiconductor layer due to an insulating film having a stress, a plane orientation of the semiconductor layer, and a crystal axis in a channel length direction, difference in mobility between the n-channel field-effect transistor and the p-channel field-effect transistor can be reduced, whereby current driving capabilities and response speeds of the n-channel field-effect transistor and the p-channel field-effect can be comparable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to semiconductor devices having aso-called SOI (silicon on insulator) structure in which a semiconductorlayer is provided on an insulating surface.

2. Description of the Related Art

As an alternative to an integrated circuit using a silicon wafer whichis manufactured by thinly slicing a single-crystal semiconductor ingot,an integrated circuit using a semiconductor substrate which is referredto as a silicon on insulator (hereinafter also referred to as “SOI”) inwhich a thin single-crystal semiconductor layer is provided on aninsulating surface has been developed. The integrated circuit using anSOI substrate has attracted attention as a semiconductor integratedcircuit which reduces parasitic capacitance between a transistor and thesubstrate and improves the performance of a semiconductor integratedcircuit.

As a method for manufacturing SOI substrates, a hydrogen ionimplantation separation method is known (e.g., see Reference 1: JapanesePublished Patent Application No. 2000-124092). A hydrogen ionimplantation separation method is a method by which hydrogen ions areimplanted into a silicon wafer to form a microbubble layer at apredetermined depth from the surface, and the microbubble layer is usedas a cleavage plane to bond a thin silicon layer to another siliconwafer. In addition to performing heat treatment for separation of asilicon layer, it is necessary to perform heat treatment in oxidizingatmosphere in order to form an oxide film on the silicon layer, toremove the oxide film, and then to perform heat treatment at from 1000to 1300° C. to increase bonding strength.

On the other hand, a semiconductor device in which an insulatingsubstrate such as high heat resistance glass is provided with a siliconlayer is disclosed (e.g., see Reference 2: Japanese Published PatentApplication No. H11-163363). This semiconductor device has a structurein which the entire surface of a crystallized glass having a distortionpoint of 750° C. or more is protected by an insulating silicon film, anda silicon layer obtained by a hydrogen ion implantation separationmethod is fixed to the insulating silicon film.

SUMMARY OF THE INVENTION

Microfabrication has been a road map for technical development in afield of semiconductor devices, and thus, the field of the semiconductordevices has been developed. So far, as the semiconductor devices areminiaturized, higher speed operation can be realized, and thus low powerconsumption has been achieved.

However, there is a need for achieving higher performance and lowerpower consumption of semiconductor devices without depending on only amicrofabrication technique.

In a transistor in which the above-described SOI substrate is used,carrier mobility of a p-channel transistor is lower compared to carriermobility of an n-channel transistor. When carrier mobility is differentbetween the n-channel transistor and the p-channel transistor, thecurrent driving capability is different between the n-channel transistorand the p-channel transistor each having the same area. Therefore, theresponse speed is also different between the n-channel transistor andthe p-channel transistor.

In order to make the response speed of the p-channel transistorcomparable to that of the n-channel transistor, it is necessary to makea channel width of the p-channel transistor wider than a channel widthof the n-channel transistor. Therefore, an area occupied by then-channel transistor and an area occupied by the p-channel transistorbecome unbalanced. As a result, there is a space unnecessary for acircuit arrangement and semiconductor devices have been prevented frombeing highly integrated.

Accordingly, it is an object to achieve higher performance and lowerpower consumption in semiconductor devices having an SOI structure. Inaddition, it is another object to provide semiconductor devicesincluding more highly integrated and higher performance semiconductorelements.

A plurality of semiconductor elements such as n-channel field-effecttransistors and p-channel field-effect transistors which include asemiconductor layer which is separated from a semiconductor substrateand is bonded to a supporting substrate having an insulating surface arestacked with an insulating layer interposed therebetween.

In the present invention, by controlling a distortion caused to achannel formation region of a semiconductor layer, a plane orientationof the semiconductor layer, and a crystal axis in a channel lengthdirection, difference in mobility between an n-channel field-effecttransistor and a p-channel field-effect transistor which are included ina semiconductor device is reduced, and current driving capabilities andswitching speeds of the n-channel field-effect transistor and thep-channel field-effect transistor are more comparable to each other.Therefore, an area occupied by the n-channel field-effect transistor andan area occupied by the p-channel field-effect transistor can be nearlycomparable, whereby efficiency of circuit design is improved and smallersemiconductor devices with higher integration and higher performance canbe provided.

The distortion is caused to the channel formation region of thesemiconductor layer by forming an insulating film over the semiconductorlayer, and the distortion caused to the channel formation region of thesemiconductor layer can be controlled to be either a compressivedistortion or a tensile distortion depending on which stress theinsulating film has, a compressive stress or a tensile stress. In thepresent invention, the distortion is caused to the channel formationregion of the semiconductor layer at least in a channel lengthdirection.

By causing a distortion appropriate to a conductivity type of afield-effect transistor in a channel length direction of a semiconductorlayer, mobility of the field-effect transistor can be improved. Forexample, when a p-channel field-effect transistor is a distortiontransistor in which a compressive distortion is caused to a channelformation region of a semiconductor layer, mobility can be improved.

Since a semiconductor layer which is separated and transferred from asemiconductor substrate is used, a crystal plane orientation and acrystal axis of a channel length direction in the field-effecttransistor can be controlled by selecting a semiconductor substrate. Byemploying an appropriate crystal plane orientation and an appropriatecrystal axis, the carrier effective mass is decreased and mobility ofthe field-effect transistor can be improved. Therefore, higherperformance field-effect transistor can be realized.

The term “channel length” used herein means a length (width) of achannel formation region in a direction parallel to a direction in whichcarriers flow. The term “channel width” used herein means a length(width) of a channel formation region in a direction perpendicular to adirection in which carriers flow.

A semiconductor layer in a lower layer and a semiconductor layer in anupper layer which are stacked with a gate insulating layer, aninsulating layer, an insulating film in the upper layer, and the likeinterposed therebetween are electrically connected by a wiring layerwhich penetrates the gate insulating layer, an interlayer insulatinglayer, and the insulating layer in the upper layer. In the case wherethe semiconductor layer in the lower layer and the semiconductor layerin the upper layer are stacked so as to be overlapped with each other,the wiring layer may be formed to penetrate the semiconductor layer inthe upper layer and to be in contact with the semiconductor layer in thelower layer. If semiconductor layers are stacked closely so as to beoverlapped with each other, higher integration of the semiconductordevice can be achieved.

Since a high performance semiconductor element can have a stackedstructure, a semiconductor device can be more highly integrated.Accordingly, the circuit area of the more highly integratedsemiconductor device is decreased and wiring capacitance is reduced.Therefore, low power consumption can be realized.

After formation of a semiconductor element in the lower layer, aninterlayer insulating layer which covers the semiconductor element inthe lower layer is formed and an insulating layer which is bonded to asemiconductor layer in the upper layer is formed over the interlayerinsulating layer. Therefore, a bond between the semiconductor layer ofthe semiconductor element in the upper layer and the insulating layer isfacilitated, whereby the reliability of the semiconductor device and theyield can be improved.

In addition, when the semiconductor layers of field-effect transistorsare bonded to different insulating layers, parasitic capacitance of thesemiconductor layers or parasitic capacitance of gate electrode layersof the field-effect transistors can be reduced.

A mode of a semiconductor device according to the present invention is asemiconductor device including a substrate having an insulating surface;a first field-effect transistor having a first semiconductor layer, afirst gate insulating layer, and a first gate electrode layer, over thesubstrate having the insulating surface; a first insulating film whichcovers the first field-effect transistor; an interlayer insulating layerover the first insulating film; a second field-effect transistor havinga second semiconductor layer, a second gate insulating layer, and asecond gate electrode layer, over the interlayer insulating layer; and asecond insulating film which covers the second field-effect transistor,and which have a stacked structure. The first semiconductor layer of thefirst field-effect transistor is bonded to the first insulating layerformed between the first semiconductor layer and the substrate havingthe insulating surface and is provided over the substrate having theinsulating surface. The second semiconductor layer of the secondfield-effect transistor is bonded to the second insulating layerprovided over the interlayer insulating layer and is provided over thefirst field-effect transistor. In the case where the conductivity typeof the first field-effect transistor is an n-type and the conductivitytype of the second field-effect transistor is a p-type, the secondinsulating film has a compressive stress.

In n-channel and p-channel semiconductor layers, it is preferable that aplane orientation of a surface which is parallel to an insulatingsurface be {110} and a crystal axis in a channel length direction be<110>. This is because difference in mobility between the n-channelfield-effect transistor and the p-channel field-effect transistor can bereduced.

Higher performance and lower power consumption can be achieved insemiconductor devices having an SOI structure. In addition, efficiencyof circuit design is improved so that a circuit area is decreased,whereby smaller semiconductor devices can be provided and semiconductordevices including more highly integrated and higher performancesemiconductor elements can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B illustrate a semiconductor device of the presentinvention;

FIGS. 2A and 2B illustrate a method for manufacturing a semiconductordevice of the present invention;

FIGS. 3A to 3D illustrate a method for manufacturing a semiconductordevice of the present invention;

FIGS. 4A to 4D illustrate a method for manufacturing a semiconductordevice of the present invention;

FIGS. 5A to 5E illustrate a method for manufacturing a semiconductordevice of the present invention;

FIGS. 6A to 6D illustrate a method for manufacturing a semiconductordevice of the present invention;

FIGS. 7A to 7F illustrate a method for manufacturing a semiconductordevice of the present invention;

FIGS. 8A to 8D illustrate a method for manufacturing a semiconductordevice of the present invention;

FIG. 9 is a block diagram illustrating a structure of a microprocessorwhich can be obtained using a semiconductor device of the presentinvention;

FIG. 10 is a block diagram illustrating a structure of an RFCPU whichcan be obtained using a semiconductor device of the present invention;

FIGS. 11A to 11G illustrate application examples of a semiconductordevice of the present invention;

FIG. 12 illustrates a semiconductor device of the present invention;

FIGS. 13A and 13B illustrate a semiconductor device of the presentinvention;

FIGS. 14A to 14C illustrate application examples of a semiconductordevice of the present invention;

FIGS. 15A to 15D illustrate a method for manufacturing a semiconductordevice of the present invention;

FIGS. 16A to 16D illustrate a method for manufacturing a semiconductordevice of the present invention;

FIGS. 17A to 17C illustrate a method for manufacturing a semiconductordevice of the present invention;

FIGS. 18A and 18B illustrate a manufacturing apparatus of asemiconductor device which can be applied to the present invention;

FIG. 19 illustrates a manufacturing apparatus of a semiconductor devicewhich can be applied to the present invention;

FIG. 20 illustrates a manufacturing apparatus of a semiconductor devicewhich can be applied to the present invention;

FIGS. 21A and 21B illustrate a semiconductor device of the presentinvention;

FIGS. 22A and 22B illustrate a semiconductor device of the presentinvention;

FIG. 23 illustrates a semiconductor device of the present invention; and

FIG. 24 illustrates a semiconductor device of the present invention.

DETAILED DESCRIPTION OF THE INVENTION Embodiment Mode

Embodiment modes of the present invention are described in detail withreference to the drawings. Note that the present invention is notlimited to the following description and it will be readily appreciatedby those skilled in the art that modes and details can be modified invarious ways without departing from the spirit and the scope of thepresent invention. Accordingly, the present invention should not beconstrued as being limited to the description of the embodiment modes tobe given below. Note that in a structure of the present inventiondescribed below, like portions or portions having like functions indifferent drawings are denoted by the like reference numerals andrepeated description thereof is omitted.

Embodiment Mode 1

A method for manufacturing a semiconductor device of the presentinvention is described with reference to FIGS. 1A and 1B, FIGS. 2A and2B, FIGS. 3A to 3D, and FIGS. 4A to 4D. This embodiment mode describes acomplementary metal oxide semiconductor (CMOS) as an example ofsemiconductor devices which include more highly integrated and higherperformance semiconductor elements.

In this embodiment mode, semiconductor elements having a semiconductorlayer which is separated from a semiconductor substrate and is bonded toa supporting substrate having an insulating surface are stacked with aninsulating layer interposed therebetween. The semiconductor elementwhich is to be stacked includes a semiconductor element having asemiconductor layer in which a distortion is caused to a channelformation region by an insulating film. A single-crystal semiconductorsubstrate is preferably used as the semiconductor substrate, and asingle-crystal semiconductor layer is preferably formed as thesemiconductor layer which is separated from the semiconductor substrateand is bonded to the supporting substrate.

FIG. 1A illustrates a semiconductor device of this embodiment mode. Ablocking layer 109, an insulating layer 104, a protective layer 121, afield-effect transistor 230, an insulating film 210, an interlayerinsulating layer 211, an insulating layer 212, a field-effect transistor231, an insulating film 222, and an interlayer insulating layer 223 areformed over a supporting substrate 101 having an insulating surface. Thefield-effect transistor 230 and the field-effect transistor 231 are thinfilm transistors which include a thin semiconductor layer. Thefield-effect transistor 230 includes a semiconductor layer 119 whichincludes impurity regions 208 a and 208 b, which are a source region anda drain region, and a channel formation region 209, a gate insulatinglayer 205, and a gate electrode layer 206. The field-effect transistor231 includes a semiconductor layer 216 which includes impurity regions220 a and 220 b, which are a source region and a drain region, and achannel formation region 221, a gate insulating layer 217, and a gateelectrode layer 218. A wiring layer 226 is formed to be in contact withthe impurity region 208 b. A wiring layer 224 is formed to be in contactwith the impurity region 220 a. A wiring layer 225 which is formed to bein contact with the impurity region 208 a and the impurity region 220 belectrically connects the field-effect transistor 230 and thefield-effect transistor 231.

Although FIG. 1A illustrates an example of a semiconductor device inwhich the interlayer insulating layer 211 is formed over thefield-effect transistor 230 in order to planarize irregularities due tothe field-effect transistor 230, it is not necessary to form theinterlayer insulating layer 211 as in a semiconductor device illustratedin FIG. 23. In the semiconductor device illustrated in FIG. 23, theinsulating layer 212 which is bonded to the semiconductor layer 216 isformed to be in contact with the insulating film 210 over thefield-effect transistor 230.

FIG. 1A illustrates an example of a semiconductor device in which thewiring layer 225 and the wiring layer 226 are formed in an opening (acontact hole) which successively penetrates the gate insulating layer205, the insulating film 210, the interlayer insulating layer 211, theinsulating layer 212, the gate insulating layer 217, the insulating film222, and the interlayer insulating layer 223. FIG. 1B illustratesanother example of electrical connection between the field-effecttransistor 230 and the field-effect transistor 231.

The wiring layers 224, 225, and 226 have a stacked structure in whichwiring layers 240 a, 240 b, 240 c, and 240 d which are embedded wiringlayers are formed to fill openings which are contact holes and thenwiring layers 241 a, 241 b, and 241 c are formed over the embeddedwiring layers. The wiring layers may include a barrier metal film or aseed film in the openings. Wiring layers 233, 235, and 236 in FIG. 1Band FIGS. 2A and 2B are wiring layers having a stacked structure similarto the wiring layers 224, 225, and 226.

In the case where a contact hole which penetrates a plurality of layersis formed, a side surface of the contact hole may have a plurality oftaper angles. For example, in the case where an etching process includesa plurality of steps which employ different etching gasses, taper anglesand diameters of an opening may be varied depending on the etchingconditions. FIG. 21A illustrates an example in which a wiring layer isformed in a contact hole having a plurality of taper angles. In asemiconductor device in FIG. 21A, contact holes in which wiring layers242 c and 242 d which are embedded wiring layers connected to the wiringlayers 245 and 246 are formed has a first opening which is formed in thegate insulating layer 205, the insulating film 210, the interlayerinsulating layer 211, and the insulating layer 212; and a second openingwhich is formed in the gate insulating layer 217, the insulating film222, and the interlayer insulating layer 223. The first opening and thesecond opening are different in shape and the taper angle of the secondopening is larger than that of the first opening.

The wiring layer may include a barrier metal film or a seed film in theopenings. An example in which a barrier metal film is formed isillustrated in FIG. 21B. In a semiconductor device in FIG. 21B, barriermetal films 243 a, 243 b, 243 c, and 243 d are in contact with the sideand bottom surfaces of contact holes.

A semiconductor device in FIG. 1B is an example in which after theinterlayer insulating layer 211 which covers the field-effect transistor230 is formed, openings which reach the impurity regions 208 a and 208 bare formed in the gate insulating layer 205, the insulating film 210,and the interlayer insulating layer 211, and wiring layers 234 and 237which are connected to the impurity regions 208 a and 208 b,respectively, are formed. The wiring layer 233 which is formed to be incontact with the impurity region 220 b of the field-effect transistor231 and the wiring layer 234 electrically connects the field-effecttransistor 231 in the upper layer and the field-effect transistor 230 inthe lower layer. In the case of FIG. 1B, another interlayer insulatinglayer may be formed over the wiring layers 234 and 237 to planarizeirregularities due to the wiring layers 234 and 237 before theinsulating layer 212 is formed. In FIG. 1B, the insulating layer 212 isformed to be thick so as to serve as an interlayer insulating layer.

Further, the order of stacking layers of n-channel and p-channelfield-effect transistors which are included in a semiconductor device isnot limited. FIG. 1A illustrates an example in which the field-effecttransistor 230 which is an n-channel field-effect transistor includingn-type impurity regions as the impurity regions 208 a and 208 b isformed in the lower layer and the field-effect transistor 231 which is ap-channel field-effect transistor including p-type impurity regions asthe impurity regions 220 a and 220 b is formed in the upper layer. Onthe other hand, FIG. 1B illustrates an example in which the field-effecttransistor 230 which is a p-channel field-effect transistor includingp-type impurity regions as the impurity regions 208 a and 208 b isformed in the lower layer and the field-effect transistor 231 which isan n-channel field-effect transistor including n-type impurity regionsas the impurity regions 220 a and 220 b is formed in the upper layer.

In this embodiment mode, the field-effect transistor 231 is a distortiontransistor in which a distortion is caused to the channel formationregion of the semiconductor layer 216 by the insulating film 222. Thedistortion can be caused to the channel formation region of thesemiconductor layer by forming an insulating film over the semiconductorlayer. Further, the distortion caused to the channel formation region ofthe semiconductor layer can be controlled to be either a compressivedistortion or a tensile distortion depending on which stress theinsulating film has, a compressive stress or a tensile stress.

By causing a distortion appropriate to the conductivity type in thechannel length direction of the semiconductor layer of the p-channelfield-effect transistor which has low mobility, mobility of thep-channel field-effect transistor can be improved, and difference inmobility with the n-channel field-effect transistor can be reduced. Whenthe p-channel field-effect transistor is a distortion transistor inwhich a compressive distortion is caused to the channel formation regionof the semiconductor layer, mobility can be improved.

Therefore, in the semiconductor device of FIG. 1A, since thefield-effect transistor 231 is a p-channel transistor, an insulatingfilm which has a compressive stress may be used as the insulating film222.

FIG. 24 is a plan view of the semiconductor device in FIG. 1A, and FIG.1A is a cross-sectional view of the semiconductor device taken along aline Y-Z in FIG. 24. Note that in FIG. 24, the insulating film 222 andthe interlayer insulating layer 223 are omitted, and the field-effecttransistor 230 under the insulating layer 212 is indicated by a dottedline. FIG. 24 schematically illustrates a stress which is applied to thechannel formation region of the semiconductor layer 216 by arrows. Astrong distortion is not particularly caused to the semiconductor layer119 of the field-effect transistor 230 which is an n-channelfield-effect transistor. On the other hand, a compressive distortion ina direction indicated by an arrow 251 a and an arrow 251 b is caused tothe channel formation region 221 of the semiconductor layer 216 of thefield-effect transistor 231 which is a p-channel field-effect transistordue to a compressive stress of the insulating film 222. In this manner,a compressive distortion is particularly caused to a p-channelfield-effect transistor in order to improve mobility, whereby differencein mobility between the n-channel field-effect transistor and thep-channel field-effect transistor can be reduced. In addition, adistortion may also be caused to the n-channel field-effect transistorin a direction in which mobility is suppressed (a tensile distortion ora compressive distortion).

The insulating film 210 and the insulating film 222 can be formed by aCVD method (a plasma CVD method or a thermal CVD method), a sputteringmethod, or the like, and a stress can be controlled by the formationconditions (a reaction gas, pressure, temperature, high-frequencyelectric power, etc.). A nitride film can be used as the insulatingfilms 210 and 222, for example, a silicon nitride film, a siliconnitride film including oxygen (also referred to as a silicon nitrideoxide film), or the like may be used. In this embodiment mode, as theinsulating film 222, a silicon nitride film which is formed underconditions which make the silicon nitride film have a desiredcompressive stress is used.

In addition, when an insulating layer which relieves a stress is used asan insulating layer which is provided between an upper insulating filmand a lower insulating film, a semiconductor layer can be prevented frombeing influenced by an insulating film which is in a different level.Therefore, mobility of a distortion transistor can be controlled moreprecisely, less separation of a thin film occurs due to difference instress, and adverse influences on adhesiveness of a thin film due todifference in stress can be reduced, whereby the reliability of thesemiconductor device can be improved. As an insulating layer whichrelieves a stress, an oxide film or the like can be used. For example, asilicon oxide film or a silicon oxide film including nitrogen (alsoreferred to as a silicon oxynitride film) may be used. In thisembodiment mode, a silicon oxide film is used as the interlayerinsulating layer 211.

Further, in the case where field-effect transistors in which distortionsare caused in opposing directions are provided in one semiconductordevice, a field-effect transistor to which a tensile distortion iscaused and a field-effect transistor to which a compressive distortionis caused are provided in different levels, whereby insulating filmswhich have stresses in opposing directions can be provided without beingin contact with each other. Therefore, it is not necessary to design asemiconductor device which has a complicated shape and structure,whereby a high performance and high reliable semiconductor device inwhich a plurality of distortion transistors are highly integrated can bemanufactured with high productivity.

A semiconductor layer in a lower layer and a semiconductor layer in anupper layer which are stacked with a gate insulating layer, aninterlayer insulating layer, an insulating layer in the upper layer, andthe like interposed therebetween are electrically connected to eachother by a wiring layer which penetrates the gate insulating layer, theinterlayer insulating layer, and the insulating layer in the upperlayer. In the case where the semiconductor layer in the lower layer andthe semiconductor layer in the upper layer are stacked so as to beoverlapped with each other, the wiring layer may be formed to penetratethe semiconductor layer in the upper layer and to be in contact with thesemiconductor layer in the lower layer. If semiconductor layers arestacked closely so as to be overlapped with each other, higherintegration of the semiconductor device can be achieved.

FIGS. 2A and 2B illustrate semiconductor devices in which asemiconductor layer in the lower layer and a semiconductor layer in theupper layer are stacked so as to be overlapped with each other. In FIG.2A, the semiconductor layer 119 (the impurity region 208 a) in thefield-effect transistor 230 which is the semiconductor element in thelower layer and the semiconductor layer 216 (the impurity region 220 b)in the field-effect transistor 231 which is the semiconductor element inthe upper layer are stacked so as to be overlapped with each other. Thewiring layer 235 which electrically connects the field-effect transistor230 and the field-effect transistor 231 is formed to penetrate the gateinsulating layer 205, the insulating film 210, the interlayer insulatinglayer 211, the insulating layer 212, the semiconductor layer 216 (theimpurity region 220 b), the gate insulating layer 217, the insulatingfilm 222, and the interlayer insulating layer 223 and to reach thesemiconductor layer 119 (the impurity region 208 a).

While FIG. 2A illustrates an example in which the semiconductor layer119 of the field-effect transistor 230 and the semiconductor layer 216of the field-effect transistor 231 are partially overlapped with eachother, they may be substantially overlapped with each other using thesame mask as illustrated in FIG. 2B. In the present invention, sincedifference in mobility between the n-channel field-effect transistor andthe p-channel field-effect transistor is reduced and mobility of then-channel field-effect transistor and the p-channel field-effecttransistor are comparable to each other, semiconductor layers of then-channel field-effect transistor and the p-channel field-effecttransistor can have the same size and shape. The larger the area inwhich the semiconductor layers are overlapped with each other is, thehigher integration can be realized. In the semiconductor device in FIG.2B, the field-effect transistor 230 and the field-effect transistor 231are stacked to be almost completely overlapped with each other with theinterlayer insulating layer interposed therebetween. The wiring layer236 which electrically connects the field-effect transistor 230 and thefield-effect transistor 231 is formed to penetrate the gate insulatinglayer 205, the insulating film 210, the interlayer insulating layer 211,the insulating layer 212, the semiconductor layer 216 (the impurityregion 220 b), the gate insulating layer 217, the insulating film 222,and the interlayer insulating layer 223 and to reach the semiconductorlayer 119 (the impurity region 208 b).

Since a semiconductor device of the present invention has a structure inwhich semiconductor elements are stacked three dimensionally and arehighly integrated, the semiconductor elements can be aligned side byside and in contact with one insulating layer or they can be stacked inabove and below with an interlayer insulating layer interposedtherebetween and be in contact with different insulating layers.Therefore, arrangement flexibility of semiconductor elements in thesemiconductor device is increased, which can lead to further integrationand higher performance. As a semiconductor element, not to mention afield-effect transistor, a memory element which uses a semiconductorlayer can be employed; accordingly, a semiconductor device which canmeet functions required for various applications can be manufactured andprovided.

Further, since a semiconductor element which includes a semiconductorlayer separated from a single-crystal semiconductor substrate has noleak current due to grain boundaries which are generated in acrystallization step of an amorphous semiconductor layer to form apolycrystalline semiconductor layer, low power consumption of thesemiconductor device can be expected. Further, variation in thresholdvalues of semiconductor elements due to variation in crystal orientationis small. In addition, ridges on the semiconductor layer surface, whichis caused by laser crystallization of an amorphous semiconductor layer,are negligible; therefore, a gate insulating layer can be thinned.

In addition, a plurality of field-effect transistors may be formed to bein contact with one insulating layer in the same level, and a pluralityof the field-effect transistors may have one conductivity type, or aplurality of the field-effect transistors may have differentconductivity types, namely they may be n-channel field-effecttransistors and p-channel field-effect transistors.

While this embodiment mode describes a stacked structure of twofield-effect transistors, a stacked structure of more than twofield-effect transistors may be employed. A plurality of semiconductorelements can be stacked by bonding an insulating layer provided over asubstrate and a semiconductor layer.

Since the semiconductor layer which is separated and transferred fromthe semiconductor substrate is used in this embodiment mode, a crystalplane orientation and a crystal axis of a channel length direction inthe field-effect transistor can be controlled by selecting asemiconductor substrate. By employing an appropriate crystal planeorientation and an appropriate crystal axis, the carrier effective massis decreased and mobility of the field-effect transistor can beimproved, and whereby higher performance field-effect transistor can berealized.

By controlling a distortion caused to the channel formation region ofthe semiconductor layer, a plane orientation of the semiconductor layer,and a crystal axis of a channel length direction, difference in mobilitybetween the n-channel field-effect transistor and the p-channelfield-effect transistor is reduced, and current driving capabilities andresponse speeds of the n-channel field-effect transistor and thep-channel field-effect transistor become more comparable to each other.Therefore, an area occupied by the n-channel field-effect transistor andan area occupied by the p-channel field-effect transistor can be nearlycomparable, whereby efficiency of circuit design is improved and smallersemiconductor devices with higher integration and higher performance canbe provided.

Hereinafter, a method for manufacturing semiconductor devices of thisembodiment mode is described with reference to FIGS. 3A to 3D, FIGS. 4Ato 4D, FIGS. 5A to 5E, FIGS. 6A to 6D, FIGS. 7A to 7F, and FIGS. 8A to8D.

First, a method for providing a semiconductor layer over a supportingsubstrate having an insulating surface from a semiconductor substrate isdescribed with reference to FIGS. 3A to 3D and FIGS. 4A to 4C.

A semiconductor substrate 108 illustrated in FIG. 3A is cleaned, and thesemiconductor substrate 108 is irradiated with ions that are acceleratedby an electric field so as to reach a predetermined depth from thesurface of the semiconductor substrate 108 to form a fragile layer 110.Ion irradiation is performed in consideration of the thickness of asemiconductor layer which is to be transferred to a supportingsubstrate. An accelerating voltage for irradiating the semiconductorsubstrate 108 with ions is set in consideration of the thickness.

As the semiconductor substrate 108, a semiconductor substrate such as asilicon substrate or a germanium substrate, or a compound semiconductorsubstrate such as a gallium arsenide substrate or an indium phosphidesubstrate is used. The semiconductor substrate 108 is preferably asingle-crystal semiconductor substrate, but it may be a polycrystallinesemiconductor substrate. Further, a semiconductor substrate formed ofsilicon having a lattice distortion, silicon germanium in whichgermanium is added to silicon, or the like may be used. Silicon having adistortion can be formed by film formation of silicon on silicongermanium or silicon nitride which has larger lattice constant thansilicon. The semiconductor layer which is provided over the supportingsubstrate can be determined by a semiconductor substrate which isselected to be used as a base.

In addition, the crystal plane orientation of the semiconductorsubstrate 108 may be selected according to a semiconductor element whichis to be formed (a field-effect transistor in this embodiment mode). Forexample, a semiconductor substrate having a {100} crystal planeorientation, a {110} crystal plane orientation, or the like can be used.

In this embodiment mode, an ion irradiation separation method in whichthe semiconductor substrate is irradiated with ions of hydrogen, helium,or fluorine so that the ions of hydrogen, helium, or fluorine reach thepredetermined depth of the semiconductor substrate, and then, heattreatment is performed and a semiconductor layer of a superficial partis separated is employed; however, a method in which single-crystalsilicon is epitaxially grown over porous silicon, and then, a poroussilicon layer is separated and released with water jet may be used.

For example, a single-crystal silicon substrate is used as thesemiconductor substrate 108, and the surface thereof is treated withdilute hydrofluoric acid so that a natural oxide film is removed as wellas contaminant such as dust or the like attaching to the surface,whereby the surface of the semiconductor substrate 108 is cleaned.

The fragile layer 110 may be formed by irradiation with ions by anion-doping method (hereinafter simply referred to as an “ID method”) oran ion implantation method (hereinafter simply referred to as an “IImethod”). The fragile layer 110 is formed by irradiating thesemiconductor substrate 108 with ions of hydrogen, helium, or a halogentypified by fluorine. In the case of irradiation with fluorine ions as ahalogen element, BF₃ may be used as a source gas. Note that an ionimplantation method herein means a method in which a semiconductor isirradiated with an ionized gas on which mass separation is performed.

For example, when an ion implantation method is employed, massseparation is performed on an ionized hydrogen gas and H⁺ ions areselectively accelerated. H⁺ ions are implanted deeper into asemiconductor substrate compared with other ions having different masseswith the same energy and a broad concentration profile is obtained.

In an ion doping method, without mass separation of an ionized gas,plural kinds of ion species are generated in plasma and are accelerated,and then a semiconductor substrate is doped with the accelerated ionspecies. In the case where the semiconductor substrate is doped withhydrogen ions including H⁺ ions, H₂ ⁺ ions, and H₃ ⁺ ions, theproportion of H₃ ⁺ ions is 50% or more, for example, in general, theproportion of H₃ ⁺ ions is 80% and the proportion of other ions (H⁺ ionsand H₂ ⁺ ions) is 20%. Here, an ion doping also includes adding only H₃⁺ ions as ion species. In such a case, since the mass is large, a largeamount of H₃ ⁺ ions can be shallowly added to a semiconductor substrateby the same acceleration energy and a steep concentration profile isobtained.

In the case where the single-crystal silicon substrate is irradiatedwith halogen ions such as fluorine ions by an ion irradiation method,fluorine which is used for irradiation knocks out (expels) silicon atomsin silicon crystal lattices, so that blank portions are formedeffectively to make microvoids in the fragile layer. In this case, thevolume of the microvoids formed in the fragile layer is changed by heattreatment at a relatively low temperature, and a thin single-crystalsemiconductor layer can be formed by separation along the fragile layer.After irradiation with fluorine ions, irradiation with hydrogen ions maybe performed so that hydrogen may be contained in the voids. It ispreferable to effectively utilize the action of fluorine ions andhydrogen ions in such a manner because separation is performed along thefragile layer which is formed to release a thin semiconductor layer fromthe semiconductor substrate by utilization of change in volume of themicrovoids which are formed in the fragile layer.

Irradiation may be performed with ions of one atom or the same kindatoms with different masses. For example, in the case of irradiationwith hydrogen ions, it is preferable that H⁺, H₂ ⁺, and H₃ ⁺ ions becontained and the proportion of H₃ ⁺ ions be high. In the case ofirradiation with hydrogen ions, if H⁺, H₂ ⁺, and H₃ ⁺ ions are containedand the proportion of H₃ ⁺ ions is high, irradiation efficiency can beincreased and irradiation time can be shortened. Such a structurefacilitates release of the thin single crystal semiconductor layer.

A supporting substrate may be provided with a silicon nitride film or asilicon nitride oxide film, which prevents diffusion of an impurityelement, as a blocking layer (also referred to as a barrier layer).Further, a silicon oxynitride film may be combined as an insulating filmwhich has a function of relieving a stress. Note that a siliconoxynitride film herein means a film which contains more oxygen thannitrogen and, in the case where measurements are performed usingRutherford backscattering spectrometry (RBS) and hydrogen forwardscattering (HFS), includes oxygen, nitrogen, silicon, and hydrogen atconcentrations ranging from 50 at. % to 70 at. %, 0.5 at. % to 15 at. %,25 at. % to 35 at. %, and 0.1 at. % to 10 at. %, respectively. Further,a silicon nitride oxide film means a film which contains more nitrogenthan oxygen and, in the case where measurements are performed using RBSand HFS, includes oxygen, nitrogen, silicon, and hydrogen atconcentrations ranging from 5 at. % to 30 at. %, 20 at. % to 55 at. %,25 at. % to 35 at. %, and 10 at. % to 30 at. %, respectively. Note thatpercentages of nitrogen, oxygen, silicon, and hydrogen fall within theranges described above, when the total number of atoms contained in thesilicon oxynitride film or the silicon nitride oxide film is defined as100 at. %.

In addition, a protective layer may be formed between a semiconductorsubstrate and an insulating layer which is bonded to the semiconductorlayer. The protective layer can be formed of a single layer selectedfrom a silicon nitride layer, a silicon oxide layer, a silicon nitrideoxide layer, or a silicon oxynitride layer, or can be formed to have astacked structure which is formed of a plurality of the layers. Any ofthese layers can be formed over the semiconductor substrate before thefragile layer is formed in the semiconductor substrate. Further, thelayers may be formed over the semiconductor substrate after the fragilelayer is formed in the semiconductor substrate.

Because there is a need for irradiation with ions at a high dose forforming the fragile layer, the surface of the semiconductor substrate108 may be roughened. Therefore, a protective layer against ionirradiation, such as a silicon nitride film, a silicon nitride oxidefilm, or a silicon oxide film may be formed to have a thickness of from50 to 200 nm, may be provided on the surface which is irradiated withions.

For example, a stacked layer of a silicon oxynitride film (with athickness of from 5 to 300 nm, preferably from 30 to 150 nm (e.g., 50nm)) and a silicon nitride oxide film (with a thickness of from 5 to 150nm, preferably from 10 to 100 nm (e.g., 50 nm)) is formed by a plasmaCVD method as the protective layer over the semiconductor substrate 108.As an example, a silicon oxynitride film is formed over thesemiconductor substrate 108 to have a thickness of 50 nm, and a siliconnitride oxide film is formed thereover to have a thickness of 50 nm. Asilicon oxynitride film may be a silicon oxide film which ismanufactured by a chemical vapor deposition method using an organosilanegas.

Further, degreasing and cleaning may be performed on the semiconductorsubstrate 108 and an oxide film on the surface may be removed andthermal oxidation may be performed. As thermal oxidation, general dryoxidation may be performed; however, oxidation in an oxidizingatmosphere to which halogen-containing gas is added is preferablyperformed. For example, heat treatment is performed at a temperature of700° C. or higher in an atmosphere containing HCl at from 0.5 to 10volume % (preferably 3 volume %) with respect to oxygen. The thermaloxidation is preferably performed in a temperature range of from 950 to1100° C. The processing time may be from 0.1 to 6 hours, preferably from0.5 to 3.5 hours. The film thickness of the oxide film which is to beformed is from 10 to 1000 nm (preferably, from 50 to 200 nm), forexample, 100 nm.

As a substance including a halogen, one or more kinds selected from HF,NF₃, HBr, Cl₂, ClF₃, BCl₃, F₂, or Br₂ can be employed besides HCl.

When heat treatment is performed within such a temperature range, agettering effect by a halogen element can be obtained. Getteringparticularly has an effect of removing a metal impurity. That is, animpurity such as metal is changed into a volatile metal chloride,evaporated into the air, and removed by action of halogen. The heattreatment is effective for the semiconductor substrate 108 which issurface subjected to chemical mechanical polishing (CMP) treatment.Further, hydrogen has an effect of compensating defects at an interfacebetween the semiconductor substrate 108 and the oxide film which is tobe formed so as to reduce a local level density of the interface, andthe interface between the semiconductor substrate 108 and the oxide filmis inactivated and thus electric characteristics are stabilized.

A halogen can be contained in the oxide film formed by this heattreatment. A halogen element is contained at a concentration of from1×10¹⁷ to 5×10²⁰ atoms/cm³, so that the oxide film can serve as aprotective film which captures an impurity such as metal and preventscontamination of the semiconductor substrate 108.

For forming the fragile layer 110, an accelerating voltage and the totalnumber of ions can be controlled in accordance with the thickness of afilm deposited over the semiconductor substrate, the thickness of thesemiconductor layer which is to be separated from the semiconductorsubstrate and transferred to the supporting substrate, and ion specieswhich are used for irradiation.

For example, a hydrogen gas is used for a material, and irradiation withions is performed at an accelerating voltage of 40 kV with the totalnumber of ions of 2×10¹⁶ ions/cm² by an ion doping method, so that thefragile layer can be formed. In the case where the thickness of theprotective layer is increased and irradiation with ions is performedunder the same condition to form the fragile layer, the thickness of asemiconductor layer which is separated from the semiconductor substrateand transferred to the supporting substrate can be decreased. Forexample, although it depends on the ratio of ion species (H⁺ ions, H₂ ⁺ions, and H₃ ⁺ ions), the above-described condition for the formation ofthe fragile layer in the semiconductor substrate on which a siliconoxynitride film (with a thickness of 50 nm) and a silicon nitride oxidefilm (with a thickness of 50 nm) are stacked as a protective layer givesa semiconductor layer, which is transferred to the supporting substrate,with a thickness of approximately 120 nm. When a silicon oxynitride film(with a thickness of 100 nm) and a silicon nitride oxide film (with athickness of 50 nm) are stacked as a protective layer over thesemiconductor substrate, the thickness of the semiconductor layer whichis transferred to the supporting substrate is approximately 70 nm.

When helium (He) or hydrogen is used as a source gas, irradiation isperformed with an accelerating voltage in the range of from 10 to 200 kVand with a dose in the range of from 1×10¹⁶ to 6×10¹⁶ ions/cm² to formthe fragile layer. When helium is used as a source gas, irradiation canbe performed with He⁺ ions as main ions without mass separation.Further, if hydrogen is used as a source gas, irradiation can beperformed with H₃ ⁺ ions or H₂ ⁺ ions as main ions. Ion species changedepending on a plasma generation method, pressure, the supply of asource gas, and an accelerating voltage.

As an example of formation of the fragile layer, a silicon oxynitridefilm (with a thickness of 50 nm), a silicon nitride oxide film (with athickness of 50 nm), and a silicon oxide film (with a thickness of 50nm) are stacked as a protective layer over the semiconductor substrate,and irradiation with hydrogen is performed at an acceleration voltage of40 kV and a dose of 2×10¹⁶ ions/cm² to form the fragile layer in thesemiconductor substrate. Then, a silicon oxide film (with a thickness of50 nm) is formed as an insulating layer over the silicon oxide film,which is the top layer of the protective layer. As another example offormation of the fragile layer, a silicon oxide film (with a thicknessof 100 nm) and a silicon nitride oxide film (with a thickness of 50 nm)are stacked as a protective layer over the semiconductor substrate, andirradiation with hydrogen is performed at an acceleration voltage of 40kV and a dose of 2×10¹⁶ ions/cm² to form the fragile layer in thesemiconductor substrate. Then, a silicon oxide film (with a thickness of50 nm) is formed as an insulating layer over the silicon nitride oxidefilm, which is the top layer of the protective layer. Note that thesilicon oxynitride film and the silicon nitride oxide film may be formedby a plasma CVD method, and the silicon oxide film may be formed by aCVD method using an organosilane gas.

When a glass substrate which is used in the electronics industry, suchas an aluminosilicate glass substrate, an aluminoborosilicate glasssubstrate, or a barium borosilicate glass substrate is used as thesupporting substrate 101, the glass substrate contains a slight amountof alkali metal such as sodium, and this slight amount of impurity mayadversely affect the characteristics of a semiconductor element such asa transistor. The silicon nitride oxide film prevents such metalimpurities contained in the supporting substrate 101 from diffusing fromthe supporting substrate 101 to the semiconductor substrate side. Notethat a silicon nitride film may be formed as an alternative to thesilicon nitride oxide film. A stress relieving layer such as a siliconoxynitride film or a silicon oxide film is preferably provided betweenthe semiconductor substrate and the silicon nitride oxide film. When astacked structure of the silicon nitride oxide film and the siliconoxynitride film is provided, diffusion of impurities to thesemiconductor substrate can be prevented and stress distortion can bereduced.

Next, as illustrated in FIG. 3B, a silicon oxide film is formed as theinsulating layer 104 over a surface which is to form a bond with asupporting substrate. As the silicon oxide film, a silicon oxide filmformed by a chemical vapor deposition method using an organosilane gasis preferable. Alternatively, a silicon oxide film formed by a chemicalvapor deposition method using a silane gas can be employed. Filmformation by a chemical vapor deposition method is performed at atemperature, for example, 350° C. or lower (specifically 300° C.) atwhich the fragile layer 110 that is formed in a single-crystalsemiconductor substrate is not degassed. In addition, heat treatmentwhich releases allows a single-crystal semiconductor layer or apolycrystalline semiconductor layer to be separated from asingle-crystal semiconductor substrate or a polycrystallinesemiconductor substrate employs a temperature which is higher than atemperature for formation of the insulating layer 104.

The insulating layer 104 has a smooth surface and forms a hydrophilicsurface. As this insulating layer 104, a silicon oxide film ispreferable. In particular, a silicon oxide film which is formed by achemical vapor deposition method using an organosilane gas ispreferable. Examples of organosilane gas that can be used aresilicon-containing compounds, such as tetraethoxysilane (TEOS) (chemicalformula: Si(OC₂H₅)₄), trimethylsilane (TMS) ((CH₃)₃SiH),tetramethylsilane (chemical formula: Si(CH₃)₄),tetramethylcyclotetrasiloxane (TMCTS), octamethylcyclotetrasiloxane(OMCTS), hexamethyldisilazane (HMDS), triethoxysilane (SiH(OC₂H₅)₃), andtrisdimethylaminosilane (SiH(N(CH₃)₂)₃). Note that when the siliconoxide film is formed by a chemical vapor deposition method usingorganosilane as a source gas, a gas which provides oxygen is preferablymixed. As a gas which provides oxygen, oxygen, nitrous oxide, nitrogendioxide, or the like can be used. Further, an inert gas such as argon,helium or nitrogen, or a hydrogen gas can be mixed.

Alternatively, the insulating layer 104 can be a silicon oxide filmwhich is formed by a chemical vapor deposition method using silane suchas monosilane, disilane, or trisilane as a source gas. Also in thiscase, a gas which provides oxygen, an inert gas, or the like ispreferably mixed. In addition, a silicon oxide film which is to be aninsulating layer which is bonded with a semiconductor layer may includechlorine. Film formation by a chemical vapor deposition method isperformed at a temperature, for example, 350° C. or lower at which thefragile layer 110 that is formed in the semiconductor substrate 108 isnot degassed. In addition, heat treatment which releases a semiconductorlayer from a single-crystal semiconductor substrate or a polycrystallinesemiconductor substrate employs a temperature which is higher than atemperature for film formation. Note that a chemical vapor depositionmethod herein includes a plasma CVD method, a thermal CVD method, and aphoto-CVD method.

Alternatively, as the insulating layer 104, silicon oxide can be formedby heat treatment of the semiconductor 108 in an oxidizing atmosphere byreacting the semiconductor substrate 108 with oxygen radicals, bychemically oxidizing the semiconductor substrate 108 with an oxidizingreagent, or the like. Further, the insulating layer 104 may be formed byreaction between the organosilane gas and oxygen radicals or nitrogenradicals.

The insulating layer 104 which has a smooth and hydrophilic surface isformed to have a thickness of from 5 to 500 nm, preferably from 10 to200 nm. With this thickness, it is possible to smooth surface roughnessof the semiconductor substrate 108 and also to ensure smoothness of theinsulating layer 104. In addition, a distortion of the insulating layer104 and the supporting substrate that are bonded can be eased. Thesurface of the insulating layer 104 is preferably set as follows: anarithmetic mean roughness Ra is less than 0.8 nm and a root-mean-squareroughness Rms is less than 0.9 nm; more preferably, Ra is 0.4 nm or lessand Rms is 0.5 nm or less; and still more preferably, Ra is 0.3 nm orless and Rms is 0.4 nm or less. For example, Ra is 0.27 nm and Rms is0.34 nm. In this specification, Ra is arithmetic mean roughness, Rms isroot-mean-square roughness, and the measurement area is 2 μm² or 10 μm².

The supporting substrate 101 may be provided with a silicon oxide filmsimilar to the insulating layer 104. In other words, in bonding thesemiconductor layer 102 to the supporting substrate 101, a strong bondcan be formed when the insulating layer 104 formed of a silicon oxidefilm preferably using organosilane as a material is provided over one orboth surfaces which are bonded.

FIG. 3C illustrates a mode in which the supporting substrate 101 and asurface of the semiconductor substrate 108 which is provided with theinsulating layer 104 are disposed in close contact with each other andbonded. The surfaces that are bonded to each other are sufficientlycleaned. The surfaces of the supporting substrate 101 and the insulatinglayer 104 over the semiconductor substrate 108 may be cleaned bymegasonic cleaning or the like. Further, the surfaces may be cleanedwith ozone water after the megasonic cleaning to remove an organicsubstance and improve the hydrophilicity of the surfaces.

By allowing the supporting substrate 101 and the insulating layer 104face each other and pressing a part thereof from the outside, thesupporting substrate 101 and the insulating layer 104 attract each otherby increase in van der Waals forces or contribution of hydrogen bondingdue to local reduction in distance between the bonding surfaces.Further, since the distance between the supporting substrate 101 and theinsulating layer 104, which face each other, in a region which isadjacent to the pressed part is reduced, a region which is stronglyinfluenced by van der Waals forces or a region to which hydrogen bondingcontributes is widened. Accordingly, bonding proceeds and spreads to theentire bonding surfaces. For example, a pressure of approximately from100 to 5000 kPa may be used.

In order to form a strong bond, the surfaces may be activated. Forexample, the surfaces which are to form a bond are irradiated with anatomic beam or an ion beam. In the case of using an atomic beam or anion beam, a neutral atom beam of an inert gas or ion beam of an inertgas such as argon or the like can be used. Further, plasma irradiationor radical treatment is performed. Such a surface treatment facilitatesa bond between different kinds of materials even in a temperature rangeof from 200 to 400° C.

Further, in order to improve bonding strength at a bond interfacebetween the supporting substrate and the insulating layer, heattreatment is preferably performed. For example, heat treatment isperformed in a temperature condition of from 70 to 350° C. (e.g., at200° C. for 2 hours) with an oven, a furnace, or the like.

In FIG. 3D, after the supporting substrate 101 and the semiconductorsubstrate 108 are attached to each other, heat treatment is performed torelease the semiconductor substrate 108 from the supporting substrate101 with the fragile layer 110 serving as a separation plane. When theheat treatment is performed at, for example, from 400 to 700° C., thevolume of minute voids formed in the fragile layer 110 is changed, whichenables separation along the fragile layer 110. Since the insulatinglayer 104 is bonded to the supporting substrate 101, the semiconductorlayer 102 having the same crystallinity as the semiconductor substrate108 is left over the supporting substrate 101.

The heat treatment in the temperature range of from 400 to 700° C. maybe successively performed with the same apparatus as the above-describedheat treatment for improving the bonding strength or with a differentapparatus. For example, after heat treatment in a furnace at 200° C. for2 hours, the temperature is increased to near 600° C. and held for 2hours, the temperature is decreased to a temperature ranging from 400°C. to room temperature, and then the substrates are taken out of thefurnace. Alternatively, heat treatment may be performed with atemperature increasing from room temperature. Further alternatively,heat treatment may be performed in a furnace at 200° C. for 2 hours, andthen, in a temperature range of from 600 to 700° C. with a rapid thermalannealing (RTA) apparatus for from 1 to 30 minutes (e.g., at 600° C. for7 minutes or at 650° C. for 7 minutes).

By the heat treatment in the temperature range of from 400 to 700° C.,bonding between the insulating layer and the supporting substrate shiftsfrom hydrogen bonding to covalent bonding, the volume of the elementwhich has been added to the fragile layer expands and the pressures ofthe microvoids rise, whereby the semiconductor layer can be releasedfrom the semiconductor substrate. After the heat treatment, thesupporting substrate and the semiconductor substrate are in a statewhere one of them is placed over the other, and the supporting substrateand the semiconductor substrate can be separated from each other withoutapplication of large force. For example, one substrate provided over theother substrate is lifted by a vacuum chuck, so that the substrate canbe easily separated. At this time, if the lower substrate is fixed witha vacuum chuck or a mechanical chuck, the supporting substrate and thesemiconductor substrate can be separated from each other withouthorizontal deviation.

Note that although an example in which the semiconductor substrate 108is smaller than the supporting substrate 101 is illustrated in FIGS. 3Ato 3D and FIGS. 4A to 4D, the present invention is not limited thereto,and the semiconductor substrate 108 and the supporting substrate 101 maybe the same size or the semiconductor substrate 108 may be larger thanthe supporting substrate 101.

FIGS. 4A to 4D illustrate steps of forming a semiconductor layer with aninsulating layer which is to be bonded to the semiconductor layer andwhich is provided on the supporting substrate 101. FIG. 4A illustrates astep in which the semiconductor substrate 108, which is provided with asilicon oxide film serving as the protective layer 121, is irradiatedwith ions that are accelerated by an electric field so as to reach apredetermined depth to form the fragile layer 110. Ion irradiation isperformed similarly to the case of FIG. 3A. Formation of the protectivelayer 121 over the surface of the semiconductor substrate 108 canprevent the surface from being damaged and from losing its planarity dueto ion irradiation. Further, the protective layer 121 has an effect ofpreventing diffusion of impurities into the semiconductor layer 102which is formed using the semiconductor substrate 108.

FIG. 4B illustrates a step in which the supporting substrate 101, overwhich the blocking layer 109 and the insulating layer 104 are formed,and a surface of the protective layer 121, which is formed over thesemiconductor substrate 108, are disposed to be in close contact witheach other and bonded. The insulating layer 104 over the supportingsubstrate 101 is disposed in close contact with the protective layer 121of the semiconductor substrate 108 so that they are bonded to eachother.

After that, the semiconductor substrate 108 is released as illustratedin FIG. 4C. Heat treatment for releasing the semiconductor layer isperformed similarly to the case of FIG. 3D. In this manner, asemiconductor substrate illustrated in FIG. 4C can be obtained.

As the supporting substrate 101, a substrate having an insulatingproperty or a substrate having an insulating surface can be used, and itis possible to employ any of a variety of glass substrates that are usedin the electronics industry and referred to as non-alkali glasssubstrates, such as an aluminosilicate glass substrate, analuminoborosilicate glass substrate, or a barium borosilicate glasssubstrate. Further, a quartz substrate, a ceramic substrate, a sapphiresubstrate, a metal substrate whose surface is coated with an insulatinglayer, or the like can be used.

Through the above-described process, as illustrated in FIG. 4C, theinsulating layer 104 and the semiconductor layer 102, which is separatedfrom the semiconductor substrate 108, are provided over the supportingsubstrate 101 having the insulating surface.

The semiconductor layer 102 provided over the supporting substrate 101is etched into an island shape. A mask 117 is formed over thesemiconductor layer 102. A semiconductor layer 119 having an islandshape is formed by etching the semiconductor layer 102 using the mask117. While FIGS. 4A to 4C illustrate an example in which the protectivelayer and the insulating layer below the semiconductor layer are notetched in the etching treatment for forming the semiconductor layer 119,the protective layer and the insulating layer may also be etched in theetching treatment for forming the semiconductor layer 119. In this case,the protective layer and the insulating layer reflect the shape of thesemiconductor layer 119 having an island-shape and are provided onlyunder the semiconductor layer 119.

The semiconductor layer which is separated from the semiconductorsubstrate and is transferred to the supporting substrate may havecrystal defects due to the separation step and the ion irradiation step,and may lose surface planarity and have irregularities. When atransistor is formed as a semiconductor element using the semiconductorlayer, it is difficult to form a thin gate insulating layer with highwithstand voltage on the semiconductor layer with these irregularities.In addition, if the semiconductor layer has a crystal defect,performance and reliability of the transistor are adversely affected;for example, a local interface state density with the gate insulatinglayer is increased.

Therefore, the semiconductor layer is preferably irradiated with anelectromagnetic wave such as laser light to reduce crystal defects.Irradiation with an electromagnetic wave can melt the semiconductorlayer at least partially and can reduce crystal defects in thesemiconductor layer. Note that an oxide film (a film that is formed bythe spontaneous oxidation or a chemical oxidation) formed on the surfaceof the semiconductor layer may be removed with dilute hydrofluoric acidbefore irradiation with an electromagnetic wave.

Any electromagnetic wave may be used as long as they provide high energyto the semiconductor layer, and laser light can be preferably used.

The energy supply to the semiconductor layer can be performed by amethod mainly utilizing heat conduction, which can be achieved bycolliding particles having high energy with the semiconductor layer. Asa heat source for supplying particles having high energy, plasma such asnormal-pressure plasma, high-pressure plasma, or a thermal plasma jet,or flame of a gas burner or the like can be used. Alternatively, anelectron beam or the like can be used as a heat source.

A wavelength of an electromagnetic wave is set so that it is absorbed bythe semiconductor layer. The wavelength can be determined inconsideration of the skin depth and the like of the electromagneticwave. For example, the wavelength of electromagnetic wave can be from190 to 600 nm. Further, electromagnetic wave energy can be determined byconsidering the wavelength of the electromagnetic wave, the skin depthof the electromagnetic wave, the thickness of the semiconductor layer tobe irradiated, or the like.

A laser emitting laser light can be a continuous wave laser, aquasi-continuous wave laser, or a pulsed laser. A pulsed laser ispreferable for partial melting. For example, a gas laser such as anexcimer laser such as a KrF laser, an Ar laser, a Kr laser, or the likecan be used. Alternatively, as a solid state laser, a YAG laser, a YVO₄laser, a YLF laser, a YAlO₃ laser, a GdVO₄ laser, a KGW laser, a KYWlaser, an Alexandrite laser, a Ti:sapphire laser, a Y₂O₃ laser, or thelike can be used. While an excimer laser is a pulsed laser, some solidlasers such as a YAG laser can also be used as a continuous laser, aquasi-continuous laser, and a pulsed laser. Note that in a solid statelaser, any of the second harmonic to the fifth harmonic of a fundamentalwave is preferably used. In addition, a semiconductor laser such as GaN,GaAs, GaAlAs, InGaAsP, or the like can be used.

As long as the semiconductor layer can be irradiated withelectromagnetic wave energy, lamp light may be used. For example, lightemitted from an ultraviolet lamp, a black light, a halogen lamp, a metalhalide lamp, a xenon arc lamp, a carbon arc lamp, a high pressure sodiumlamp, or a high pressure mercury lamp may be used. Flash annealing withthe above-described lamp light may be used. Since flash annealing whichis performed by preferably using a halogen lamp, a xenon lamp, or thelike requires only a very short treatment time, increase in temperatureof the supporting substrate can be suppressed.

A shutter; a reflector such as a mirror, a half mirror, or the like; anoptical system including a cylindrical lens, a convex lens, or the likemay be provided to adjust the shape or path of the electromagnetic wave.

Note that, as for an irradiation method of the electromagnetic wave, thesemiconductor layer can be selectively irradiated with light (theelectromagnetic wave) or the semiconductor layer can be irradiated withlight (the electromagnetic wave) by scanning the light (theelectromagnetic wave) in the XY directions. In this case, a polygonmirror or a galvanometer mirror is preferably used for the opticalsystem.

Irradiation with the electromagnetic wave can be performed in anatmosphere which contains oxygen, such as an atmospheric atmosphere orin an inert atmosphere such as a nitrogen atmosphere. To performirradiation with the electromagnetic wave in an inert atmosphere,irradiation with the electromagnetic wave may be performed in anairtight chamber, and the atmosphere in this chamber may be controlled.In the case where a chamber is not used, a nitrogen atmosphere can beformed by spraying an inert gas such as nitrogen gas or the like on asurface to be irradiated with the electromagnetic wave.

Further, polishing treatment may be performed on the surface of thesemiconductor layer to which high energy is supplied by electromagneticwave irradiation or the like and whose crystal defects of the surface isreduced. Polishing treatment can enhance the planarity of the surface ofthe semiconductor layer.

For the polishing treatment, a chemical mechanical polishing (CMP)method or a liquid jet polishing method can be used. Note that thesurface of the semiconductor layer is cleaned and purified before thepolishing treatment. The cleaning may be megasonic cleaning, two-fluidjet cleaning, or the like and dust or the like of the surface of thesemiconductor layer is removed by cleaning. In addition, it ispreferable to remove a film that is formed by spontaneous oxidation orthe like on the surface of the semiconductor layer by using dilutehydrofluoric acid to expose the semiconductor layer.

In addition, the surface of the semiconductor layer may be subjected topolishing treatment (or etching treatment) before the electromagneticwave irradiation.

In this embodiment mode, when a single-crystal silicon substrate is usedas the semiconductor substrate 108, a single-crystal silicon layer canbe obtained as the semiconductor layer 119. Further, since a method formanufacturing an SOI substrate of a semiconductor device in thisembodiment mode allows a process temperature to be 700° C. or lower, aglass substrate can be used as the supporting substrate 101. That is, atransistor in this embodiment mode can be formed over a glass substrateand a single-crystal silicon layer can be employed as the semiconductorlayer. Accordingly, a transistor with high performance and highreliability which can, for example, operate at high speed and lowdriving voltage and have a low subthreshold swing and high electronfield-effect mobility can be manufactured over a supporting substratesuch as a glass substrate.

Next, a method for manufacturing the semiconductor device illustrated inFIG. 1A which employs the above-described SOI substrate is describedwith reference to FIGS. 7A to 7F and FIGS. 8A to 8D.

In FIG. 7A, the blocking layer 109, the insulating layer 104, theprotective layer 121, and the semiconductor layer 119 are formed overthe supporting substrate 101. The semiconductor layer 119, the blockinglayer 109, the insulating layer 104, and the protective layer 121correspond to those in FIGS. 4A to 4D. Note that while an example inwhich the SOI substrate having the structure illustrated in FIG. 7A isemployed is given here, the SOI substrate having another structuredescribed in this specification can be employed.

To the semiconductor layer 119, a p-type impurity such as boron,aluminum, or gallium or an n-type impurity such as phosphorus or arsenicmay be added to a region where an n-channel field-effect transistor or ap-channel field-effect transistor is to be formed in order to control athreshold voltage.

The semiconductor layer 119 may be further etched to have an islandshape in accordance with arrangement of the semiconductor elements.

An oxide film over the semiconductor layer is removed and a gateinsulating layer 205 is formed to cover the semiconductor layer 119.

The gate insulating layer 205 may be formed using silicon oxide, or maybe formed with a stacked structure of silicon oxide and silicon nitride.The gate insulating layer 205 may be formed by depositing an insulatingfilm by a plasma CVD method or a low-pressure CVD method. Alternatively,the gate insulating layer 205 may be formed by solid-phase oxidation orsolid-phase nitridation with plasma treatment because a gate insulatinglayer formed by oxidizing or nitriding a semiconductor layer by plasmatreatment is dense, has high withstand voltage, and is highly reliable.

Further, as the gate insulating layer 205, a high dielectric constantmaterial such as zirconium dioxide, hafnium oxide, titanium dioxide, ortantalum pentoxide may be used. When a high dielectric constant materialis used for the gate insulating layer 205, gate leak current can bereduced.

The gate electrode layer 206 is formed over the gate insulating layer205 (see FIG. 7B). The gate electrode layer 206 can be formed by asputtering method, an evaporation method, a CVD method, or the like. Thegate electrode layer 206 may be formed using an element selected fromtantalum (Ta), tungsten (W), titanium (Ti), molybdenum (Mo), aluminum(Al), copper (Cu), chromium (Cr), or neodymium (Nd), or an alloymaterial or compound containing any of those elements as its maincomponent. Further, as the gate electrode layer 206, a semiconductorfilm typified by a polycrystalline silicon film doped with an impurityelement such as phosphorus can be used, or an AgPdCu alloy may be used.

The impurity regions 208 a and 208 b, which are n-type impurity regions,are formed by adding an impurity element 207 imparting n-typeconductivity using the gate electrode layer 206 as a mask. In thisembodiment mode, phosphine (PH₃) is used as a doping gas containing animpurity element. Here, doping is performed such that the impurityregions 208 a and 208 b contain the impurity element imparting n-typeconductivity at a concentration of approximately from 5×10¹⁹ to 5×10²⁰atoms/cm³. In addition, the channel formation region 209 is formed inthe semiconductor layer 119 (see FIG. 7C).

The impurity regions 208 a and 208 b are n-type high-concentrationimpurity regions and serve as a source and a drain.

Heat treatment, intense light irradiation, or laser light irradiationmay be performed to activate the impurity element, which can repairplasma damage to the gate insulating layer and to the interface betweenthe gate insulating layer and the semiconductor layer as well asactivate the impurity element.

Subsequently, an interlayer insulating layer which covers the gateelectrode layer and the gate insulating layer is formed. In thisembodiment mode, the insulating film 210 and the interlayer insulatinglayer 211 are laminated to form a stacked structure. The insulating film210 contains hydrogen and serves as a protective film. Further, theinsulating film 210 can cause a distortion to the channel formationregion of the semiconductor layer 119.

Further, heat treatment is performed in a nitrogen atmosphere at from300 to 550° C. for 1 to 12 hours to hydrogenate the semiconductor layer.Preferably, this heat treatment is performed at from 400 to 500° C. Thisstep terminates dangling bonds of the semiconductor layer with hydrogenwhich is contained in the insulating film 210, which is the interlayerinsulating layer. In this embodiment mode, the heat treatment isperformed at 410° C. for one hour.

In the present invention, the interlayer insulating layer 211 is formedto relieve irregularities on the surface which are generated by thesemiconductor layer, the gate electrode layer, and the like and toobtain a planarized surface. Accordingly, the interlayer insulatinglayer 211 is formed to have a thickness with which the surface thereofis planarized. Note that the surface may be planarized by chemicalmechanical polishing (CMP).

The interlayer insulating layer 211 may be formed of a silicon nitridefilm, a silicon nitride film including oxygen (a silicon nitride oxidefilm), a silicon oxide film including nitride (a silicon oxynitridefilm), or a silicon oxide film by using a sputtering method or a plasmaCVD method. Alternatively, a single layer or a stacked structure ofthree or more layers which include another insulating film containingsilicon may be used.

The interlayer insulating layer 211 can be formed of a material selectedfrom inorganic insulating substances, such as aluminum nitride (AlN),aluminum oxynitride (AlON), aluminum nitride oxide (AlNO) containingmore nitrogen than oxygen, aluminum oxide, diamond-like carbon (DLC),nitrogen-containing carbon (CN), or the like. Further, a siloxane resinmay be used. Note that a siloxane resin refers to a resin including anSi—O—Si bond. Siloxane is composed of a skeleton formed by the bond ofsilicon (Si) and oxygen (O), in which an organic group containing atleast hydrogen (such as an alkyl group and an aryl group) is used as asubstituent. Alternatively, a fluoro group may be included in theorganic group.

Alternatively, an organic insulating material which can withstandsubsequent heat treatment may be used. As such an organic insulatingmaterial, polyimide, acrylic polymer, polyamide, polyimide amide,benzocyclobutene-based resin, or polysilazane can be given. A coatedfilm which is formed by a coating method and has favorable planarity maybe used as the interlayer insulating layer 211.

Dip coating, spray coating, a doctor knife, a roll coater, a curtaincoater, a knife coater, a CVD method, an evaporation method, or the likecan be used for forming the interlayer insulating layer 211. Theinterlayer insulating layer 211 may be formed by a droplet dischargemethod. If a droplet discharge method is used, a material solution canbe saved. In addition, a method capable of transferring or drawing apattern like a droplet discharge method, for example, a printing method(a method for forming a pattern, such as screen printing or offsetprinting) can be used.

The insulating layer 212 is formed over the interlayer insulating layer211 as an insulating layer which is bonded to a second semiconductorlayer. The material and forming step of the insulating layer 212 may besimilar to those for the insulating layer 104. The insulating layer 212can be a smooth layer (an arithmetic mean roughness Ra is less than 0.3nm (a measurement area 10 μm²)) and a silicon oxide film or siliconoxynitride film, a laminate of a silicon nitride film and a siliconoxide film stacked in that order over the interlayer insulating layer211, or a laminate of a silicon oxynitride film and a silicon oxide filmstacked in that order over the interlayer insulating layer 211. Theinsulating layer 212 is preferably formed by a PECVD method at a lowtemperature of 350° C. or less. For example, in this embodiment mode, asilicon oxide film is formed as the insulating layer 212, usingtetraethoxysilane as an organosilane gas by a chemical vapor depositionmethod. A silicon nitride film or a silicon oxynitride film preventsimpurities from diffusing from the interlayer insulating layer 211through the insulating layer 212 to the semiconductor layer 216 and thegate insulating layer 217 which are formed thereover.

A semiconductor layer 215 is bonded to the insulating layer 212 to formthe semiconductor layer 215 over the interlayer insulating layer 211 asthe semiconductor layer 102 is bonded to the insulating layer 104 and isseparated from the semiconductor substrate 108 (see FIG. 7E). Thesemiconductor layer 215 is separated from the semiconductor substrate213 provided with a fragile layer 214 and is bonded to the insulatinglayer 212 with heat treatment. Note that it is preferable that this heattreatment be performed at a temperature lower than the temperature forthe above-described hydrogenation step of the semiconductor layer 119.

The semiconductor layer 215 may be irradiated with laser light to reducecrystal defects. The surface of the semiconductor layer 215 may besubjected to polishing treatment. Polishing treatment can enhance theplanarity of the surface of the semiconductor layer 215.

Note that in n-channel and p-channel semiconductor layers, it ispreferable that a plane orientation of a surface which is parallel to aninsulating surface be {110} and a crystal axis in a channel lengthdirection be <110>. This is because difference in mobility between then-channel field-effect transistor and the p-channel field-effecttransistor can be reduced.

Then, the semiconductor layer 215, which is a thin film, is selectivelyetched to form the semiconductor layer 216 having an island shape overthe insulating layer 212 (see FIG. 7F).

The gate insulating layer 217 and the gate electrode layer 218 areformed over the semiconductor layer 216 (see FIG. 8A).

The impurity regions 220 a and 220 b, which are p-type impurity regions,are formed by adding an impurity element 219 imparting p-typeconductivity using the gate electrode layer 218 as a mask. Doping isperformed such that the impurity regions 220 a and 220 b contain theimpurity element imparting p-type conductivity at a concentration ofapproximately from 1×10²⁰ to 5×10²¹ atoms/cm³. In addition, the channelformation region 221 is formed in the semiconductor layer 216 (see FIG.8B). The impurity regions 220 a and 220 b are p-type high-concentrationimpurity regions and serve as a source and a drain.

Subsequently, an interlayer insulating layer which covers the gateelectrode layer and the gate insulating layer is formed. In thisembodiment mode, the interlayer insulating layer has a stacked structureof the insulating film 222 which contains hydrogen and serves as aprotective film and the interlayer insulating layer 223.

Further, heat treatment is performed in a nitrogen atmosphere at from300 to 550° C. for 1 to 12 hours to hydrogenate the semiconductor layer.Preferably, this heat treatment is performed at from 400 to 500° C. Thisstep terminates dangling bonds of the semiconductor layer with hydrogenwhich is contained in the insulating film 222, which is the interlayerinsulating layer. In this embodiment mode, the heat treatment isperformed at 410° C. for one hour. This heat treatment may also serve asthe heat treatment for the semiconductor layer 119 and the insulatingfilm 210.

In the present invention, the interlayer insulating layer 223 is formedto relieve irregularities on the surface which are generated by thesemiconductor layer, the gate electrode layer, and the like and toobtain a planarized surface. Accordingly, the interlayer insulatinglayer 223 is formed to have a thickness with which the surface thereofis planarized. Note that the surface may be planarized by chemicalmechanical polishing (CMP).

The gate insulating layer 217, the gate electrode layer 218, theinsulating film 222, and the interlayer insulating layer 223 correspondto the gate insulating layer 205, the gate electrode layer 206, theinsulating film 210, and the interlayer insulating layer 211,respectively, and they can be formed of similar materials and by similarsteps.

Then, contact holes (openings) which reach the semiconductor layer 119or the semiconductor layer 216 are formed in the gate insulating layer205, the insulating film 210, the interlayer insulating layer 211, theinsulating layer 212, the gate insulating layer 217, the insulating film222, and the interlayer insulating layer 223 using a mask formed of aresist. Etching may be performed once or plural times in accordance witha selectivity of a material which is used. The gate insulating layer205, the insulating film 210, the interlayer insulating layer 211, theinsulating layer 212, the gate insulating layer 217, the insulating film222, and the interlayer insulating layer 223 are selectively removed byetching to form openings which reach the impurity regions 208 a and 208b or the impurity regions 220 a and 220 b, which are source regions anddrain regions.

A method and a condition of the etching may be set as appropriatedepending on the materials of the gate insulating layer 205, theinsulating film 210, the interlayer insulating layer 211, the insulatinglayer 212, the gate insulating layer 217, the insulating film 222, andthe interlayer insulating layer 223 in which the contact holes areformed. Wet etching, dry etching, or both of them can be used asappropriate. In this embodiment mode, dry etching is used. As an etchinggas, a chlorine-based gas typified by Cl₂, BCl₃, SiCl₄ or CCl₄; afluorine-based gas typified by CF₄, SF₆ or NF₃; or O₂ can be used asappropriate. Further, an inert gas may be added to an etching gas to beused. As an inert element to be added, one or a plurality of elementsselected from He, Ne, Ar, Kr, or Xe can be used.

As an etchant of wet etching, a hydrofluoric acid-based solution such asa mixed solution of ammonium hydrogen fluoride and ammonium fluoride maybe used.

A conductive film is formed to cover the openings, and the conductivefilm is etched to form the wiring layers 224, 225, and 226, which areelectrically connected to portions of source regions and drain regionsand serve as source electrode layers and drain electrode layers. Thewiring layers can be formed by forming a conductive film by a PVDmethod, a CVD method, an evaporation method, or the like and thenetching the conductive film into a desired shape. Alternatively,conductive layers can be selectively formed in predetermined positionsby a droplet discharge method, a printing method, an electroplatingmethod, or the like. Further, a reflow method or a damascene method maybe used. The wiring layers are formed of a metal such as Ag, Au, Cu, Ni,Pt, Pd, Ir, Rh, W, Al, Ta, Mo, Cd, Zn, Fe, Ti, Zr, or Ba; and Si or Ge;or an alloy or nitride thereof. Further, a laminate thereof may beemployed.

In this embodiment mode, the wiring layers 240 a and 240 b are formed asembedded wiring layers to fill contact holes formed in the gateinsulating layer 217, the insulating film 222, and the interlayerinsulating layer 223; and the wiring layers 240 c and 240 d are formedas embedded wiring layers to fill contact holes formed in the gateinsulating layer 205, the insulating film 210, the interlayer insulatinglayer 211, the insulating layer 212, the gate insulating layer 217, theinsulating film 222, and the interlayer insulating layer 223 (see FIG.8C). The wiring layers 240 a, 240 b, 240 c, and 240 d, which are theembedded wiring layers, are formed by forming a conductive film havingan enough thickness to fill the contact holes and polishing theconductive film by a CMP method or the like so that the conductive filmcan remain only in contact hole portions and an unnecessary part of theconductive film are removed.

As lead wiring layers, the wiring layers 241 a, 241 b, and 241 c areformed over the wiring layers 240 a, 240 b, 240 c, and 240 d which areembedded, whereby the wiring layers 224, 225, and 226 are formed.

Through the above-described steps, a semiconductor device having a CMOSstructure, including the field-effect transistor 230, which is ann-channel field-effect transistor, and the field-effect transistor 231,which is a p-channel field-effect transistor, can be manufactured (seeFIG. 8D). Note that the field-effect transistor 230 and the field-effecttransistor 231 are electrically connected by the wiring layer 225.

The field-effect transistor 230 is bonded to the insulating layer 104and is provided over the supporting substrate 101, while thefield-effect transistor 231 is bonded to the insulating layer 212 whichis formed over the interlayer insulating layer 211 covering thefield-effect transistor 230 and is provided over the interlayerinsulating layer 211. The field-effect transistor 230 and thefield-effect transistor 231 are stacked.

In the present invention, since a high performance semiconductor elementcan have a stacked structure, a semiconductor device can be more highlyintegrated. The circuit area of the more highly integrated semiconductordevice is smaller and wiring capacitance is reduced. Therefore, lowpower consumption can be realized.

In addition, in attaching the semiconductor layers to the supportingsubstrate, the semiconductor layers are formed over different planarizedinsulating layers; therefore, the insulating layers and thesemiconductor layers can be easily bonded to each other.

As in this embodiment mode, when semiconductor layers which formfield-effect transistors of different conductivity types are formed overdifferent insulating layers, parasitic capacitance between thesemiconductor layers of the field-effect transistors of differentconductivity types and parasitic capacitance between the gate electrodelayers of the field-effect transistors of different conductivity typescan be reduced. Accordingly, a high performance semiconductor device canbe manufactured.

The field-effect transistor is not limited to the one described in thisembodiment mode, and may have a single gate structure, in which onechannel formation region is formed, a double gate structure, in whichtwo channel formation regions are formed, or a triple gate structure, inwhich three channel formation regions are formed.

In addition, while this embodiment mode describes a CMOS structure inwhich the field-effect transistors which are stacked have differentconductivity types, field-effect transistors of a single conductivitytype may be stacked.

As described above, in this embodiment mode, semiconductor devicesincluding more highly integrated and higher performance semiconductorelements can be manufactured.

Note that in the present invention, a semiconductor device refers to adevice which can function by utilizing the semiconductorcharacteristics. According to the present invention, a device having acircuit including semiconductor elements (e.g., transistors, memoryelements, or diodes) or a semiconductor device such as a chip includinga processor circuit can be manufactured.

Embodiment Mode 2

This embodiment mode describes an example of a step for bonding asemiconductor layer from a semiconductor substrate to a supportingsubstrate, which is different from that in Embodiment Mode 1. Therefore,repetitive descriptions for the same components as or components havingsimilar functions to the components in Embodiment Mode 1 are omitted.

In this embodiment mode, when a semiconductor layer is transferred froma semiconductor substrate, the semiconductor substrate is selectivelyetched (this step is also referred to as a groove processing), and aplurality of semiconductor layers which are divided to have the size ofsemiconductor elements to be manufactured are transferred to asupporting substrate. Thus, a plurality of island-shaped semiconductorlayers can be formed over the supporting substrate. The semiconductorlayers which are processed into an element size in advance aretransferred; therefore, the semiconductor layers can be transferred tothe supporting substrate in units of the semiconductor layers.Therefore, the size and shape of the semiconductor substrate are notlimited. Accordingly, semiconductor layers can be more efficientlytransferred to a large-sized supporting substrate.

The semiconductor layer which is thus formed over the supportingsubstrate may be etched so that the shape of the semiconductor layer isprocessed, modified, and controlled precisely. Accordingly, it ispossible to repair an error in a formation position and a defect in theshape of the semiconductor layer which are caused by the diffraction ofthe exposed light in the formation of a resist mask or by positionalmisalignment in the bonding step of the transferring process.

Accordingly, a plurality of semiconductor layers having desired shapescan be formed over the supporting substrate with a high yield.Therefore, a semiconductor device which includes high performancesemiconductor elements and integrated circuit which are more precise canbe manufactured over a large-sized substrate with high throughput andhigh productivity.

FIG. 5A illustrates a state in which a protective layer 154 and asilicon nitride film 152 are formed over a semiconductor substrate 158.The silicon nitride film 152 is used as a hard mask in performing grooveprocessing on the semiconductor substrate 158. The silicon nitride film152 may be formed by depositing silane and ammonia by a vapor depositionmethod.

Next, ion irradiation is performed to form a fragile layer 150 in thesemiconductor substrate 158 (see FIG. 5B). The ion irradiation isperformed in consideration of the thickness of a semiconductor layerwhich is to be transferred to a supporting substrate. An acceleratingvoltage for irradiating the semiconductor substrate 158 with ions isdetermined taking such a thickness into consideration, so that a deeppart of the semiconductor substrate 158 is irradiated. With thistreatment, the fragile layer 150 is formed in a region at a certaindepth from the surface of the semiconductor substrate 158.

The groove processing is performed in consideration of the shapes ofsemiconductor layers of semiconductor elements. That is, in order totransfer the semiconductor layer of the semiconductor element to thesupporting substrate, the groove processing is performed on thesemiconductor substrate 158 such that a semiconductor layer which is tobe transferred remains as a convex portion.

A mask 153 is formed of photoresist. The silicon nitride film 152 andthe protective layer 154 are etched using the mask 153, whereby aprotective layer 162 and a silicon nitride layer 163 are formed (seeFIG. 5C).

Next, the semiconductor substrate 158 is etched using the siliconnitride layer 163 as a hard mask to form the semiconductor substrate 158having a fragile layer 165 and a semiconductor layer 166 (see FIG. 5D).In the present invention, a semiconductor region which is interposedbetween the fragile layer 165 and the protective layer 162 and isprocessed into a convex shape is referred to as the semiconductor layer166, as illustrated in FIG. 5D.

The depth of etching the semiconductor substrate 158 is determined asappropriate in consideration of the thickness of the semiconductor layer166 which is transferred to the supporting substrate. The thickness ofthe semiconductor layer 166 can be determined according to the depthwhere hydrogen ions reach by irradiation. The surface of the groove inthe semiconductor substrate 158 is preferably lower than the fragilelayer. In this groove processing, if the surface of the groove in thesemiconductor substrate 158 is set to be lower than the fragile layer,the fragile layer can be left only under a region of the semiconductorlayer 166 which is to be released.

The silicon nitride layer 163 on the surface is removed (see FIG. 5E).Then, the surface of the protective layer 162 and a supporting substrate151 are bonded to each other (see FIG. 6A).

The surface of the supporting substrate 151 is provided with a blockinglayer 159 and an insulating layer 157. The blocking layer 159 isprovided so as to prevent impurities such as sodium ions from diffusingfrom the supporting substrate 151 and contaminating the semiconductorlayer. Note that, in the case where it is negligible that diffusion ofimpurities from the supporting substrate 151 may cause adverse effectson the semiconductor layer, the blocking layer 159 can be omitted.Meanwhile, the insulating layer 157 is provided to form a bond with theprotective layer 162.

The bond can be formed by disposing the protective layer 162 of thesemiconductor substrate 158 and the insulating layer 157 of thesupporting substrate, the surfaces of which are cleaned, in closecontact with each other. The bond can be formed at room temperature.This bond is performed at an atomic level, and a strong bond is formedat room temperature by van der Waals forces. Since groove processing isperformed on the semiconductor substrate 158, a convex portion whichincludes the semiconductor layer 166 comes into contact with thesupporting substrate 151.

After a bond is formed between the semiconductor substrate 158 and thesupporting substrate 151, heat treatment is performed to release asemiconductor layer 166 from the semiconductor substrate 158 and tofasten the semiconductor layer 166 to the supporting substrate 151, asillustrated in FIG. 6B. The volume of microvoids formed in the fragilelayer 150 is changed and then a cleavage section is generated along thefragile layer 150, whereby the semiconductor layer is released. Afterthat, heat treatment is preferably performed to further strengthen thebond. Thus, the semiconductor layer is formed over the insulatingsurface. FIG. 6B illustrates a state in which the semiconductor layer166 is bonded to the supporting substrate 151.

In this embodiment mode, since the semiconductor layers which areprocessed into an element size in advance are transferred, transfer tothe supporting substrate can be performed in units of the semiconductorlayers; therefore, the size and shape of the semiconductor substrate arenot limited. Accordingly, semiconductor layers having various shapes canbe formed over the semiconductor substrate. For example, the shapes ofthe semiconductor layers can be freely formed in accordance with a maskof a light-exposure apparatus which is used for etching, a stepper ofthe light-exposure apparatus for forming a mask pattern, and a panel orchip size of a semiconductor device which is cut from a large-sizedsubstrate.

The semiconductor layer 166 may be directly used as a semiconductorlayer of a semiconductor element, or may be etched to process the shape.

FIGS. 6C and 6D illustrate an example in which the semiconductor layer166 which is transferred is etched to process the shape. A mask 167 isformed to expose a periphery of the semiconductor layer 166, which is anunnecessary part.

The semiconductor layer 166 is etched using the mask 167 to form asemiconductor layer 169. In this embodiment mode, a part of theprotective layer 162 under the semiconductor layer is etched togetherwith the semiconductor layer, resulting in a protective layer 168 (seeFIG. 6D). In this manner, when the shape of the semiconductor layer isfurther processed after the semiconductor layer is transferred to thesupporting substrate, misalignment of a region where the semiconductorlayer is formed, defects in shape, or the like which occur in amanufacturing process can be repaired.

FIGS. 5A to 5E and FIGS. 6A to 6D illustrate an example in which asemiconductor layer is transferred to an insulating layer over thesupporting substrate. Note that this embodiment mode can be employed forforming a semiconductor layer over the insulating layer which is over aninterlayer insulating layer, as a semiconductor layer of a semiconductorelement which is in the upper layer.

This embodiment mode can be implemented in combination with EmbodimentMode 1, as appropriate.

Embodiment Mode 3

This embodiment mode describes an example of a step for bonding asemiconductor layer from a semiconductor substrate to a supportingsubstrate, which is different from that in Embodiment Mode 1. Therefore,repetitive descriptions for the same components as or components havingsimilar functions to the components in Embodiment Mode 1 are omitted.

This embodiment mode describes an example in which after a semiconductorlayer is separated from a semiconductor substrate, the semiconductorlayer is bonded to a supporting substrate.

As described in Embodiment Mode 2 with reference to FIGS. 5A to 5E, thefragile layer is formed in the semiconductor substrate, and a groove isformed. The groove processing is performed in consideration of the shapeof a semiconductor layer of a semiconductor element. That is, in orderto transfer the semiconductor layer of the semiconductor element to thesupporting substrate, the groove processing is performed on asemiconductor substrate 301 such that a portion which is transferred asthe semiconductor layer remains as a convex portion. In FIG. 15A, thesemiconductor substrate 301, a fragile layer 302, a semiconductor layer308 which is a part of the semiconductor substrate 301, and aninsulating film 304 are formed. In this embodiment mode, silicon oxideis used for the insulating film 304.

Next, heat treatment is performed, whereby microvoids in the fragilelayer 302 are increased in volume. As a result, the semiconductorsubstrate 301 is separated at the fragile layer 302; thus, thesemiconductor layer 308 is released with the insulating film 304 fromthe semiconductor substrate 301. For example, the heat treatment may beperformed in a temperature range of from 400° C. to 600° C.

Note that the heat treatment may be performed using dielectric heatingwith high frequency waves such as microwaves. The heat treatment usingthe dielectric heating can be performed by irradiating the semiconductorsubstrate 301 with high frequency waves in the range of from 300 MHz to3 THz which is generated at a high-frequency generator. Specifically,for example, irradiation is performed with a microwave of 2.45 GHz at900 W for 14 minutes to expand the volume of the microvoids in thefragile layer; thus, the semiconductor substrate 301 is finallyseparated.

Then, as illustrated in FIG. 15B, a collet 305 is fixed to theinsulating film 304 formed over the semiconductor layer 308, and thesemiconductor layer 308 is pulled apart from the semiconductor substrate301. Even if separation of the semiconductor substrate 301 by the aboveheat treatment is incomplete, force is applied using the collet 305,whereby the semiconductor layer 308 is completely released from thesemiconductor substrate 301 and a semiconductor layer 303 can beobtained. The collet 305 can be a means that can be selectively fixed toone of the semiconductor layers 308, such as a chuck such as a vacuumchuck or a mechanical chuck, or a microneedle tipped with an adhesive.FIG. 15B illustrates a case where a vacuum chuck is used as the collet305.

As the adhesive which is adhered to a microneedle, an epoxy-basedadhesive, a ceramic-based adhesive, a silicone-based adhesive, a lowtemperature coagulant, or the like can be used. As the low temperaturecoagulant, for example, MW-1 (made by Eminent Supply Corporation) can beused. MW-1 has a freezing point of 17° C. and has a bonding effect at atemperature less than or equal to the freezing point (preferably at 10°C. or less) and does not have a bonding effect at a temperature of 17°C. or more (preferably approximately 25° C.).

Note that hydrogenation may be performed on the semiconductor substrate301 before the separation of the semiconductor substrate 301. Thehydrogenation is performed, for example, at 350° C. in a hydrogenatmosphere for approximately two hours.

Next, as illustrated in FIG. 15C, the semiconductor layer 303 and asupporting substrate 310 are attached to each other so that a surfaceexposed by the release of the semiconductor layer 303 faces thesupporting substrate 310. In this embodiment mode, because an insulatingfilm 311 is formed over the supporting substrate 310, the insulatingfilm 311 and the semiconductor layer 303 are bonded to each other,whereby the semiconductor layer 303 and the supporting substrate 310 canbe attached to each other. After the semiconductor layer 303 and theinsulating film 311 are bonded to each other, heat treatment in atemperature range of from 400° C. to 600° C. is preferably performed inorder to further strengthen the bond.

The bonding is formed by van der Waals forces, so that a strong bond canbe formed even at room temperature. Note that, since the above-describedbonding can be formed at low temperature, various substrates can be usedas the supporting substrate 310. As the supporting substrate 310, forexample, a substrate such as a quartz substrate or a sapphire substratecan be used as well as a glass substrate made of aluminosilicate glass,barium borosilicate glass, aluminoborosilicate glass, or the like.Further, as the supporting substrate 310, a semiconductor substrateformed of silicon, gallium arsenide, indium phosphide, or the like canbe used. Alternatively, a metal substrate such as a stainless steelsubstrate may be used as the supporting substrate 310.

Note that the insulating film 311 is not necessarily formed on thesurface of the supporting substrate 310. In the case where theinsulating film 311 is not formed, the supporting substrate 310 and thesemiconductor layer 303 can be bonded to each other. Note that byformation of the insulating film 311 on the surface of the supportingsubstrate 310, impurities such as an alkali metal or an alkaline-earthmetal can be prevented from entering the semiconductor layer 303 fromthe supporting substrate 310.

In the case where the insulating film 311 is formed, not the supportingsubstrate 310 but the insulating film 311 is bonded to the semiconductorlayer 303; therefore, kinds of substrates which can be used as thesupporting substrate 310 are further increased. A substrate formed froma flexible synthetic resin, such as plastic, generally tends to have alow upper temperature limit, but can be used as the supporting substrate310 as long as the substrate can withstand processing temperatures inthe manufacturing process.

Note that, before or after the semiconductor layer 303 is attached tothe supporting substrate 310, thermal annealing which is conducted byirradiation with laser light may be performed on a surface exposed bythe release of the semiconductor layer 303. If thermal annealing isperformed before the semiconductor layer 303 is attached to thesupporting substrate 310, the surface exposed by the release isplanarized and bonding strength can be further increased. If thermalannealing is performed after the semiconductor layer 303 is attached tothe supporting substrate 310, a part of the semiconductor layer 303 ismelted and bonding strength can be further increased.

Not only the heat treatment, but application of a high frequency wave ofapproximately 10 MHz to 1 THz to the semiconductor layer 303 may beperformed to improve the bond strength between the semiconductor layer303 and the supporting substrate 310. The application of the highfrequency wave generates frictional heat between the semiconductor layer303 and the supporting substrate 310, and the frictional heat allows apart of the semiconductor layer 303 to be melted so that thesemiconductor layer 303 is more strongly attached to the supportingsubstrate 310.

When MW-1 is used as the low temperature coagulant, first, the lowtemperature coagulant with which a microneedle is tipped is made incontact with the insulating film 304 at a temperature (e.g.,approximately 25° C.) where the low temperature coagulant does not havea bonding effect. Next, a temperature is lowered to a temperature (e.g.,approximately 5° C.) where the low temperature coagulant has a bondingeffect to solidify the low temperature coagulant, whereby themicroneedle and the insulating film 304 are fixed to each other. Afterthe semiconductor layer 303 pulled apart from the semiconductorsubstrate 301 is attached to the supporting substrate 310, thetemperature of the low temperature coagulant is raised to a temperature(e.g., approximately 25° C.) where the low temperature coagulant doesnot have a bonding effect again, whereby the microneedle can be pulledapart from the semiconductor layer 303.

The insulating film 304 over the semiconductor layer 303 is removed, andthe semiconductor layer 303 having an island shape is formed over thesupporting substrate 310 and the insulating film 311 (see FIG. 15D). Thesemiconductor layer 303 may be etched to process the shape.

As illustrated in FIGS. 15A to 15D, when the surface of thesemiconductor layer which is exposed by the separation faces thesupporting substrate, a surface with higher flatness is in contact witha gate insulating film; therefore, an interface state density betweenthe semiconductor layer and the gate insulating film can be low anduniform. Accordingly, polishing for planarizing the surface of thesemiconductor layer which comes into contact with the gate insulatingfilm can be omitted, or polishing time can be shortened, whereby costcan be suppressed and throughput can be improved.

Note that the semiconductor layer can be attached to the supportingsubstrate so that the surface of the semiconductor layer exposed by theseparation comes into contact with the gate insulating film. Thisexample is described with reference to FIGS. 16A to 16D and FIGS. 17A to17C.

In FIG. 16A, a semiconductor substrate 321, a fragile layer 322, asemiconductor layer 328 which is a part of the semiconductor substrate,and an insulating film 324 are formed as in FIG. 15A. In this embodimentmode, silicon oxide is used as the insulating film 324.

Next, as illustrated in FIG. 16B, the semiconductor substrate 321 isfixed to a holding means 325. The semiconductor substrate 321 is fixedso that the semiconductor layer 328 faces the holding means 325. Theholding means 325 can be a large-sized vacuum chuck or mechanical chuckwhich can withstand heat treatment in a later step and be fixed with aplurality of semiconductor layers (in FIG. 16B, the semiconductor layer328), specifically, a porous vacuum chuck, a noncontact vacuum chuck, orthe like. This embodiment mode describes an example in which a vacuumchuck is used as the holding means 325.

Next, heat treatment is performed, whereby microvoids in the fragilelayer 322 are increased in volume. As a result, as illustrated in FIG.16C, the semiconductor substrate 321 is separated at the fragile layer322; thus, the semiconductor layer 328, which is a part of thesemiconductor substrate 321 is released, as a semiconductor layer 323,with the insulating film 324 from the semiconductor substrate 321. Theheat treatment may be performed in a temperature range of from 400° C.to 600° C., for example.

Note that the heat treatment may be performed using dielectric heatingwith high frequency waves such as microwaves.

Before separation of the semiconductor substrate 321, hydrogenation maybe performed on the semiconductor substrate 321.

Then, as illustrated in FIG. 16D and FIG. 17A, a collet 327 is fixed tothe surface of the semiconductor layer 323 which is exposed by theseparation, and the semiconductor layer 323 is pulled apart from theholding means 325. The collet 327 can be a means that can be selectivelyfixed to the semiconductor layer 323, such as a chuck such as a vacuumchuck or a mechanical chuck, or a microneedle tipped with an adhesive.FIG. 16D and FIG. 17A illustrate a case where a vacuum chuck is used asthe collet 327.

Note that this embodiment mode describes an example in which the collet327 is fixed to the surface of the semiconductor layer 323 which isexposed by the separation; however, a protective film such as aninsulating film may be formed so as to prevent the semiconductor layer323 from being damaged by the collet 327. Note that the above-describedprotective film is removed after the semiconductor layer 323 is attachedto a supporting substrate 330 in a later step.

As the adhesive which is adhered to a microneedle, an epoxy-basedadhesive, a ceramic-based adhesive, a silicone-based adhesive, a lowtemperature coagulant, or the like can be used.

Next, as illustrated in FIG. 17B, the semiconductor layer 323 and thesupporting substrate 330 are attached to each other so that theinsulating film 324 faces the supporting substrate 330, that is, asurface opposite to the surface exposed by the separation faces thesupporting substrate 330. In this embodiment mode, because an insulatingfilm 331 is formed over the supporting substrate 330, the insulatingfilm 324 and the insulating film 331 are bonded to each other, wherebythe semiconductor layer 323 and the supporting substrate 330 can beattached to each other (see FIG. 17C). After the insulating film 324 andthe insulating film 331 are bonded to each other, heat treatment in atemperature range of from 400° C. to 600° C. is preferably performed inorder to further strengthen the bond.

The bonding is formed by van der Waals forces, so that a strong bond canbe formed even at room temperature. Since the above-described bondingcan be performed at a low temperature, various substrates can be used asthe supporting substrate 330.

Note that the insulating film 331 is not necessarily formed on thesurface of the supporting substrate 330.

There are a case where the semiconductor substrate is warped or deformedand a case where an end portion of the semiconductor substrate isslightly rounded. Further, there are cases where, in order to release asemiconductor layer from the semiconductor substrate, even if asemiconductor substrate is irradiated with hydrogen or a rare gas, ortheir ions, the irradiation is not sufficiently performed on the endportion of the semiconductor substrate, and it is difficult to release aportion of the semiconductor layer which is at the end portion of thesemiconductor substrate. Accordingly, in the case where a semiconductorsubstrate is attached to a supporting substrate, and then thesemiconductor substrate is separated to form semiconductor layers, thedistance between the semiconductor layers may be from severalmillimeters to several centimeters. However, in this embodiment mode,before the semiconductor substrate is attached to the supportingsubstrate, the semiconductor substrate is separated to form thesemiconductor layer with desired size. Thus, when the semiconductorlayers are attached to the supporting substrate, the distance betweenthe semiconductor layers can be suppressed as small as approximatelyseveral tens of micrometers, and it is easy to form a semiconductordevice including adjacent semiconductor layers.

In a method for manufacturing a semiconductor device of this embodimentmode, since a plurality of semiconductor layers can be attached to onesupporting substrate by using a plurality of semiconductor substrates,processing can be performed with high throughput. In addition, a planeorientation of the semiconductor layer can be selected as appropriate inaccordance with the polarity of a semiconductor element; therefore,mobility of the semiconductor element can be increased, and asemiconductor device that can operate at higher speed can be provided.

In addition, a plurality of semiconductor layers can be formed byseparating the semiconductor substrate at a plurality of points of thesemiconductor substrate and attached to a supporting substrate.Therefore, a plurality of semiconductor layers can be bonded atarbitrary position on a supporting substrate in accordance with polarityand layout of semiconductor elements in a semiconductor device.

This embodiment mode can be implemented in combination with EmbodimentMode 1, as appropriate.

Embodiment Mode 4

This embodiment mode describes a structure of a manufacturing apparatusof a semiconductor device which can be applied to the present invention(in particular, to Embodiment Mode 3).

FIG. 18A illustrates a structure of a manufacturing apparatus which canbe applied to the present invention (in particular, to Embodiment Mode3) as an example. The manufacturing apparatus illustrated in FIG. 18Aincludes a stage 902 over which a semiconductor substrate 901 is placed,and a stage 904 over which a supporting substrate 903 is placed. Notethat FIG. 18A illustrates an example in which the semiconductorsubstrate 901 and the supporting substrate 903 are placed over differentstages; however, the present invention is not limited to this structure.The semiconductor substrate 901 and the supporting substrate 903 can beplaced over one stage.

FIG. 18A illustrates one stage 902 over which one semiconductorsubstrate 901 is placed; however, the present invention is not limitedto this structure. For example, a manufacturing apparatus which can beapplied to the present invention may include a plurality of the stages902 over which one semiconductor substrate 901 is placed. Alternatively,a plurality of the semiconductor substrates 901 may be placed over thestage 902.

The manufacturing apparatus illustrated in FIG. 18A includes a collet905 which is fixed to a semiconductor layer formed by separation of thesemiconductor substrate 901 and attaches the semiconductor layer to apredetermined position of the supporting substrate 903. The collet 905can be a means that can be selectively fixed to one of the semiconductorlayers, such as a chuck such as a vacuum chuck or a mechanical chuck, ora microneedle tipped with an adhesive.

In addition, the manufacturing apparatus illustrated in FIG. 18A atleast includes a collet driving portion 906 which controls the positionof the collet 905, a stage driving portion 907 which controls positionsof the stage 902 and the stage 904, and a CPU 908 which controlsoperations of the collet driving portion 906 and the stage drivingportion 907 in accordance with positional information of the collet orpositional information of the stage.

The positional information of the collet or the positional informationof the stage can be obtained based on positional information where asemiconductor layer is formed in the semiconductor substrate 901 andwhere the semiconductor layer is attached to the supporting substrate903. Note that the manufacturing apparatus illustrated in FIG. 18A maybe provided with a camera having an image sensor such as a chargecoupled device (CCD) in order to position the semiconductor substrate901 or the supporting substrate 903.

When a heat sink for absorbing and dissipating heat of the semiconductorsubstrate 901 is provided over the stage 902 and a microneedle tippedwith a low temperature coagulant is provided as the collet 905, thetemperature of the semiconductor substrate 901 can be efficientlylowered by using the heat sink.

In addition, a manufacturing apparatus which can be applied to thepresent invention may have a reversing device for picking up asemiconductor layer from the semiconductor substrate 901 and thenreversing the semiconductor layer. FIG. 18B illustrates a mode in whicha reversing device 909 is added to the manufacturing apparatusillustrated in FIG. 18A. The reversing device 909 includes a reversecollet 900 and can pick up a semiconductor layer and temporarily hold itby using the reverse collet 900. The collet 905 is fixed to a side of asemiconductor layer which is opposite to the side fixed to the reversecollet 900, whereby the collet 905 can receive the semiconductor layerfrom the reverse collet 900.

Next, in order to show a positional relationship and specific structuresof the semiconductor substrate 901, the stage 902, the supportingsubstrate 903, the stage 904, the collet 905, the collet driving portion906, and the stage driving portion 907 illustrated in FIG. 18A, aperspective diagram of them is illustrated in FIG. 19. Note that FIG. 19illustrates an example in which a stage driving portion 907 a whichcontrols the operation of the stage 902 and a stage driving portion 907b which controls the operation of the stage 904 are used.

In accordance with instructions from the CPU 908, the stage drivingportion 907 a moves the stage 902 in the X direction or the Y directionintersecting the X direction. Note that the stage driving portion 907 amay move the stage 902 in the Z direction, as well as the X direction orthe Y direction. The Z direction exists on a plane different from theplane formed by the X direction and the Y direction. Similarly, thestage driving portion 907 b moves the stage 904 in the X direction orthe Y direction intersecting the X direction. The stage driving portion907 b may move the stage 904 in the Z direction, as well as the Xdirection or the Y direction. The Z direction exists on a planedifferent from the plane formed by the X direction and the Y direction.

The collet 905 picks up one of a plurality of semiconductor layersformed by separation of the semiconductor substrate 901. Then, thecollet driving portion 906 transfers the collet 905 from thesemiconductor substrate 901 to the supporting substrate 903, while thecollet 905 holds the semiconductor layer. Note that FIG. 19 illustratesan example in which one collet 905 comes and goes between thesemiconductor substrate 901 and the supporting substrate 903; however, aplurality of the collets 905 may be used. When a plurality of thecollets 905 are used, a plurality of the collet driving portions 906 forindependently controlling the operation of each of the plurality of thecollets 905 may be prepared, or all the collets 905 may be controlled byone collet driving portion 906.

Next, FIG. 20 illustrates a mode in which a plurality of the stages 902are used in FIG. 19. FIG. 20 illustrates an example in which a stage 902a, a stage 902 b, and a stage 902 c are used, and all of the stage 902a, the stage 902 b, and the stage 902 c are controlled by the stagedriving portion 907 a. Note that a plurality of the stage drivingportions 907 a may be prepared in order to independently control theoperation of the stage 902 a, the stage 902 b, and the stage 902 c.

FIG. 20 illustrates a state in which a semiconductor substrate 901 a, asemiconductor substrate 901 b, and a semiconductor substrate 901 c areplaced over the stage 902 a, the stage 902 b, and the stage 902 c,respectively. The crystal plane orientations of the semiconductorsubstrate 901 a, the semiconductor substrate 901 b, and thesemiconductor substrate 901 c may be the same or different from oneanother.

In FIG. 20, the collet 905 picks up one of a plurality of semiconductorlayers formed by separation of the semiconductor substrate 901 a, thesemiconductor substrate 901 b, and the semiconductor substrate 901 c.Then, the collet driving portion 906 transfers the collet 905 from thesemiconductor substrate 901 a, the semiconductor substrate 901 b, or thesemiconductor substrate 901 c to the supporting substrate 903, while thecollet 905 holds the semiconductor layer. Note that FIG. 20 illustratesan example in which one collet 905 comes and goes between thesemiconductor substrate 901 a, the semiconductor substrate 901 b and thesemiconductor substrate 901 c, and the supporting substrate 903.However, a plurality of the collets 905 may be used so that at least onecollet 905 is used for each of the semiconductor substrate 901 a, thesemiconductor substrate 901 b, and the semiconductor substrate 901 c.

The manufacturing apparatus which can be applied to the presentinvention can transfer and attach a plurality of semiconductor layersformed from one semiconductor substrate 901 to desired positions overthe supporting substrate 903, as appropriate.

This embodiment mode can be implemented in combination with EmbodimentMode 3, as appropriate.

Embodiment Mode 5

This embodiment mode takes an application example of the crystal planeorientation of the semiconductor layer and the crystal axis of a channellength direction, which are used for field-effect transistors.

As described in Embodiment Modes 1 to 4, in the semiconductor device ofthe present invention, since the semiconductor layer which is separatedand transferred from the semiconductor substrate is used, a crystalplane orientation of the semiconductor layer can be selected byselecting a semiconductor substrate.

In this embodiment mode, a p-channel field-effect transistor is ap-channel distortion field-effect transistor in which a compressiondistortion is caused to a channel formation region of a semiconductorlayer.

In this embodiment mode, in both of an n-channel field-effect transistorand the p-channel field-effect transistor, a semiconductor substratewith a {110} crystal plane orientation is used and a channel lengthdirection is set to be parallel to a <110> crystal axis.

In the n-channel field-effect transistor, a crystal plane orientation ofa semiconductor layer may be {110} and a channel length direction may beset to be parallel to a <100> crystal axis.

As in this embodiment mode, by controlling a distortion caused to achannel formation region of a semiconductor layer, a plane orientationof the semiconductor layer, and a crystal axis in a channel lengthdirection, difference in mobility between an n-channel field-effecttransistor and a p-channel field-effect transistor which are included ina semiconductor device is reduced, and current driving capabilities andswitching speeds of the n-channel field-effect transistor and thep-channel field-effect transistor can be more comparable to each other.Therefore, an area occupied by the n-channel field-effect transistor andan area occupied by the p-channel field-effect transistor can be nearlycomparable, whereby efficiency of circuit design is improved and smallersemiconductor devices with higher integration and higher performance canbe provided. The circuit area can be smaller by being highly integratedand wiring capacitance can be reduced. Therefore, low power consumptioncan be realized.

This embodiment can be implemented in combination with any of EmbodimentModes 1 to 4 as appropriate.

Embodiment Mode 6

This embodiment mode describes another application example of a crystalplane orientation of a semiconductor layer and a crystal axis of achannel length direction, which are used for field-effect transistors.

As described in Embodiment Modes 1 to 4, in the semiconductor device ofthe present invention, since the semiconductor layer which is separatedand transferred from the semiconductor substrate is used, a crystalplane orientation of the semiconductor layer can be selected byselecting a semiconductor substrate.

In this embodiment mode, a p-channel field-effect transistor is ap-channel distortion field-effect transistor in which a compressiondistortion is caused to a channel formation region of a semiconductorlayer.

This embodiment mode takes an example in which the semiconductor layerswhich have different crystal plane orientations are used in then-channel field-effect transistor and the p-channel field-effecttransistor. In the p-channel field-effect transistor, a channel lengthdirection is set to be parallel to a <110> crystal axis by using asemiconductor substrate of which crystal plane orientation is {110}.

On the other hand, in the n-channel field-effect transistor, the crystalplane orientation of the semiconductor layer is set to {100}, and thechannel length direction is set to be parallel to a <110> crystal axis.

As in this embodiment mode, by controlling a distortion caused to achannel formation region of the semiconductor layer, a plane orientationof the semiconductor layer, and a crystal axis in a channel lengthdirection, difference in mobility between the n-channel field-effecttransistor and the p-channel field-effect transistor which are includedin a semiconductor device is reduced, and current driving capabilitiesand switching speeds of the n-channel field-effect transistor and thep-channel field-effect transistor are more comparable to each other.Therefore, an area occupied by the n-channel field-effect transistor andan area occupied by the p-channel field-effect transistor can be nearlycomparable, whereby efficiency of circuit design is improved and smallersemiconductor devices with higher integration and higher performance canbe provided. Further, the circuit area can be smaller by being highlyintegrated and wiring capacitance can be reduced. Therefore, low powerconsumption can be realized.

This embodiment can be implemented in combination with any of EmbodimentModes 1 to 4 as appropriate.

Embodiment Mode 7

This embodiment mode describes an example of a semiconductor devicehaving high performance and high reliability. Specifically, as anexample of the semiconductor device, examples of a microprocessor and asemiconductor device which has an arithmetic function and can transmitand receive data without contact are described.

FIG. 9 illustrates an example of a microprocessor 500 as an example of asemiconductor device. The microprocessor 500 is manufactured using thesemiconductor device formed according to the above embodiment mode. Themicroprocessor 500 has an arithmetic logic unit (also referred to as anALU) 501, an ALU controller 502, an instruction decoder 503, aninterrupt controller 504, a timing controller 505, a register 506, aregister controller 507, a bus interface (Bus I/F) 508, a read onlymemory (ROM) 509, and a memory interface (ROM I/F) 510.

An instruction input to the microprocessor 500 via the bus interface 508is input to the instruction decoder 503 and decoded. Then, theinstruction is input to the ALU controller 502, the interrupt controller504, the register controller 507, and the timing controller 505. The ALUcontroller 502, the interrupt controller 504, the register controller507, and the timing controller 505 perform various controls based on thedecoded instruction. Specifically, the ALU controller 502 generates asignal for controlling the operation of the arithmetic logic unit 501.The interrupt controller 504 judges an interrupt request from anexternal input and output device or a peripheral circuit based on itspriority or a mask state, and processes the request while a program isexecuted in the microprocessor 500. The register controller 507generates an address of the register 506, and reads and writes data fromand to the register 506 in accordance with the state of themicroprocessor 500. The timing controller 505 generates signals forcontrolling timing of operation of the arithmetic logic unit 501, theALU controller 502, the instruction decoder 503, the interruptcontroller 504, and the register controller 507. For example, the timingcontroller 505 is provided with an internal clock generator forgenerating an internal clock signal CLK2 based on a reference clocksignal CLK1, and supplies the internal clock signal CLK2 to each of theabove-described circuits. Note that the microprocessor 500 illustratedin FIG. 9 is just an example of the simplified structure, and practicalmicroprocessors have various structures depending on usage.

Since an integrated circuit is formed using a semiconductor layer withuniform crystal orientation which is bonded to a glass substrate in themicroprocessor 500, higher processing speed and lower power consumptioncan be achieved.

Next, an example of a semiconductor device provided with an arithmeticfunction by which data can be transmitted and received without contactis described with reference to FIG. 10. FIG. 10 illustrates an exampleof a computer which operates to transmit and receive signals to and froman external device by wireless communication (such a computer ishereinafter referred to as an RFCPU). An RFCPU 511 has an analog circuitportion 512 and a digital circuit portion 513. The analog circuitportion 512 includes a resonance circuit 514 having a resonantcapacitor, a rectifier circuit 515, a constant voltage circuit 516, areset circuit 517, an oscillator circuit 518, a demodulation circuit519, a modulation circuit 520, and a power supply control circuit 530.The digital circuit portion 513 includes an RF interface 521, a controlregister 522, a clock controller 523, a CPU interface 524, a centralprocessing unit 525, a random access memory 526, and a read only memory527.

The operation of the RFCPU 511 having such a structure is roughlydescribed below. The resonance circuit 514 generates inducedelectromotive force based on a signal received at an antenna 528. Theinduced electromotive force is stored in a capacitor portion 529 via therectifier circuit 515. The capacitor portion 529 is preferably formedusing a capacitor such as a ceramic capacitor or an electric doublelayer capacitor. The capacitor portion 529 is not necessarily formedover one substrate as the RFCPU 511 and may be attached as anothercomponent to a substrate having an insulating surface which is includedin the RFCPU 511.

The reset circuit 517 generates a signal which resets the digitalcircuit portion 513 to be initialized. For example, a signal which risesafter an increase in a power supply voltage is generated as the resetsignal. The oscillator circuit 518 changes the frequency and the dutyratio of a clock signal in accordance with a control signal generated bythe constant voltage circuit 516. The demodulation circuit 519 having alow pass filter, for example, binarizes changes in amplitude of receivedsignals of an amplitude shift keying (ASK) system. The modulationcircuit 520 changes the amplitude of transmission signals of anamplitude shift keying (ASK) system to be transmitted. The modulationcircuit 520 changes the resonance point of the resonance circuit 514,thereby changing the amplitude of communication signals. The clockcontroller 523 generates a control signal for changing the frequency andthe duty ratio of the clock signal in accordance with the power supplyvoltage or current consumption in the central processing unit 525. Thepower supply voltage is monitored by the power supply control circuit530.

A signal which is input to the RFCPU 511 from the antenna 528 isdemodulated by the demodulation circuit 519, and then divided into acontrol command, data, and the like by the RF interface 521. The controlcommand is stored in the control register 522. The control commandincludes reading of data stored in the read only memory 527, writing ofdata to the random access memory 526, an arithmetic instruction to thecentral processing unit 525, and the like. The central processing unit525 accesses the read only memory 527, the random access memory 526, andthe control register 522 via the CPU interface 524. The CPU interface524 has a function of generating an access signal for any one of theread only memory 527, the random access memory 526, and the controlregister 522 based on an address requested by the central processingunit 525.

As an arithmetic method of the central processing unit 525, a method canbe employed in which the read only memory 527 stores an operating system(OS) and a program is read and then executed at the time of startingoperation. Alternatively, a method can be employed in which a circuitdedicated to arithmetic is formed as an arithmetic circuit and anarithmetic processing is conducted using hardware. In a method in whichboth hardware and software are used, a method can be employed in which apart of the process is conducted in the circuit dedicated to arithmeticand the other part of the arithmetic process is conducted by the centralprocessing unit 525 using a program.

Since an integrated circuit is formed using semiconductor layers each ofwhich has a certain crystal plane orientation which are bonded to aglass substrate in the RFCPU 511, higher processing speed and lowerpower consumption can be achieved. Accordingly, even when the capacitorportion 529 which supplies electric power is miniaturized, operation fora long period of time can be secured.

Embodiment Mode 8

This embodiment mode describes an example of a structure mounting asemiconductor device according to the present invention.

An integrated circuit according to the present invention can be formedin such a way that semiconductor elements are highly integrated in threedimensions. In such a highly integrated circuit, it is preferable tomount a heat sink which efficiently dissipates heat generated by theintegrated circuit.

FIG. 22A illustrates a mode in which an integrated circuit is mounted ona printed circuit board as an example of a semiconductor deviceaccording to the present invention.

In FIG. 22A, integrated circuit packages 601 a, 601 b, and 601 c in eachof which an integrated circuit is packaged in an insulating chassiswhich are mounted on a printed circuit board 603 are provided in contactwith a heat sink 600 via heat dissipation sheets 602 a, 602 b, and 602 cwhich further improve a heat dissipation effect. The heat sink 600 isprovided so as to cover the integrated circuit packages 601 a, 601 b,and 601 c, and is electrically connected to the printed circuit board603 via conductive metal layers 604 a and 604 b, and interceptselectromagnetic waves emitted from the integrated circuit packages 601a, 601 b, and 601 c. FIG. 22A illustrates a structure in which the heatsink which covers the integrated circuits can dissipate heat from theintegrated circuits and can intercept electromagnetic waves to preventelectromagnetic interference.

FIG. 22B illustrates an example in which a heat dissipation sheet and aheat sink are directly mounted on integrated circuits. In FIG. 22B,integrated circuits 611 a and 611 b are provided in contact with a heatsink 610 via heat dissipation sheets 612 a and 612 b, and are packagedby the heat sink 610 and a chassis 613 which adheres the heat sink 610using adhesive layers 614 a and 614 b.

In this manner, when the heat sink is mounted, a semiconductor devicewith higher reliability and higher performance can be made by efficientheat dissipation and cooling.

This embodiment mode can be implemented in combination with any of theabove embodiment modes, as appropriate.

Embodiment Mode 9

This embodiment mode describes an example of a usage mode of asemiconductor device described in the above embodiment modes.Specifically, an application example of a semiconductor device capableof inputting and outputting data without contact is described withreference to the drawings. The semiconductor device to and from whichdata can be input and output without contact is also referred to as anRFID tag, an ID tag, an IC tag, an IC chip, an RF tag, a wireless tag,an electronic tag, or a wireless chip depending on the uses.

An example of a top view structure of a semiconductor device of thisembodiment mode is described with reference to FIG. 12. A semiconductordevice 2180 illustrated in FIG. 12 includes a thin film integratedcircuit 2131 including a plurality of elements such as transistors forforming a memory portion and a logic portion, and a conductive layer2132 which serves as an antenna. The conductive layer 2132 which servesas an antenna is electrically connected to the thin film integratedcircuit 2131. The field-effect transistor according to the presentinvention which is described in Embodiment Modes 1 to 3 can be appliedto the thin film integrated circuit 2131. In the present embodimentmode, a plurality of semiconductor devices having a CMOS structure isemployed in the integrated circuit 2131.

The structure of the semiconductor devices having the CMOS structure isdescribed with reference to FIGS. 13A and 13B. The field-effecttransistors included in CMOS structures 2140, 2141, 2142, and 2143 eachhave a sidewall structure in which a sidewall insulating layer 2150 isprovided on the sidewall of the gate electrode layer 2151 in each of thefield-effect transistors. These transistors also include lowconcentration impurity regions 2152 between a channel formation region2153 and a source region and a drain region (2154 a and 2154 b), whichare high concentration impurity regions, in a semiconductor layer. TheCMOS structures 2140 and 2141 are formed of a distortion field-effecttransistor in the lower layer and a distortion field-effect transistorin the upper layer which are stacked. The CMOS structures 2142 and 2143are stacked and formed of distortion field-effect transistors, arrangein parallel, which are in contact with one insulating layer. Thefield-effect transistors included in the CMOS structures 2140 and 2141are distortion field-effect transistors having high mobility in whichdistortion is caused to the channel formation region in thesemiconductor layer by insulating films (2155, 2156) that covers thefield-effect transistors.

In field-effect transistors which are included in the CMOS structure2142 and the CMOS structure 2143, by controlling a distortion caused toa channel formation region of a semiconductor layer, a plane orientationof the semiconductor layer, and a crystal axis in a channel lengthdirection, difference in mobility between an n-channel field-effecttransistor and a p-channel field-effect transistor is reduced, andcurrent driving capabilities and switching speeds of the n-channelfield-effect transistor and the p-channel field-effect transistor becomemore comparable to each other. Therefore, an area occupied by then-channel field-effect transistor and an area occupied by the p-channelfield-effect transistor can be nearly comparable, whereby efficiency ofcircuit design is improved and smaller semiconductor devices with higherintegration and higher performance can be provided.

As shown in FIGS. 13A and 13B, since the semiconductor device of thepresent invention has a structure in which semiconductor elements arestacked three dimensionally and are highly integrated, the semiconductorelements can be aligned side by side and in contact with one insulatinglayer or they can be stacked vertically with an interlayer insulatinglayer interposed therebetween and be in contact with differentinsulating layers. Therefore, arrangement flexibility of semiconductorelements in the semiconductor device is high, which can lead to furtherintegration and higher performance. As a semiconductor element, not tomention a field-effect transistor, a memory element which uses asemiconductor layer can be employed; accordingly, a semiconductor devicewhich can satisfy functions required for various applications can bemanufactured and provided.

As shown in FIGS. 13A and 13B, the conductive layer 2132 which serves asan antenna may be provided above the elements for forming the memoryportion and the logic portion; for example, the conductive layer 2132which serves as an antenna can be provided above the CMOS structures2140 and 2141 which can be formed in a similar manner to thefield-effect transistors described in the above embodiment modes with aninsulating layer 2130 interposed therebetween (see FIG. 13A).Alternatively, the conductive layer 2132 which serves as an antenna maybe provided by providing the conductive layer 2132 over a substrate 2133and then attaching the substrate 2133 and the thin film integratedcircuit 2131 each other so as to interpose the conductive layer 2132(see FIG. 13B). FIG. 13B illustrates an example in which a conductivelayer 2136 provided over the insulating layer 2130 and the conductivelayer 2132 which serves as an antenna are electrically connected to eachother with conductive particles 2134 contained in an adhesive resin2135.

Note that, although this embodiment mode describes an example in whichthe conductive layer 2132 which serves as an antenna has a coil shapeand either an electromagnetic induction method or an electromagneticcoupling method is employed, a semiconductor device of the presentinvention is not limited thereto, and a microwave method may beemployed. In the case of a microwave method, the shape of the conductivelayer 2132 which serves as an antenna may be decided as appropriatedepending on the wavelength of an electromagnetic wave which is used.

For example, when a microwave method (e.g., with an UHF band (in therange of from 860 MHz to 960 MHz), a frequency band of 2.45 GHz, or thelike) is employed as a signal transmission method of the semiconductordevice 2180, the conductive layer which serves as an antenna can beformed into a linear shape (e.g., a dipole antenna), a flat shape (e.g.,a patch antenna or an antenna having a ribbon shape), or the like.Further, the shape of the conductive layer 2132 which serves as anantenna is not limited to a straight line, and the conductive layer 2132may be a curved line, in an S-shape, or in a shape combining them inconsideration of the wavelength of the electromagnetic wave.

The conductive layer 2132 which serves as an antenna is formed of aconductive material by a CVD method, a sputtering method, a printingmethod such as screen printing or gravure printing, a droplet dischargemethod, a dispenser method, a plating method, or the like. Theconductive material is any of a metal element selected from aluminum(Al), titanium (Ti), silver (Ag), copper (Cu), gold (Au), platinum (Pt),nickel (Ni), palladium (Pd), tantalum (Ta), molybdenum (Mo), or thelike, or an alloy material or a compound containing the metal element.The conductive layer 2132 has a single layer structure or a stackedstructure.

For example, in the case where the conductive layer 2132 which serves asan antenna is formed by a screen printing method, the conductive layer2132 can be provided by selectively printing a conductive paste in whichconductive particles with a grain diameter of several nanometers toseveral tens of micrometers are dissolved or dispersed in an organicresin. As the conductive particle, fine particles or dispersivenanoparticles of one or more metals of silver (Ag), gold (Au), copper(Cu), nickel (Ni), platinum (Pt), palladium (Pd), tantalum (Ta),molybdenum (Mo), titanium (Ti), or a silver halide can be used. Inaddition, as the organic resin contained in the conductive paste, one ora plurality of organic resins serving as a binder, a solvent, adispersant, or a coating of the metal particle can be used. Typically,an organic resin such as an epoxy resin and a silicone resin can begiven as examples. Further, in forming the conductive layer, baking maybe preferably performed after the conductive paste is applied. Forexample, in the case of using fine particles (e.g., fine particles witha grain diameter of 1 nm or more and 100 nm or less) containing silveras a main component of the conductive paste, the conductive layer can beformed by baking the conductive paste in a temperature range of from 150to 300° C. to solidify it. Alternatively, fine particles containingsolder or lead-free solder as a main component may be used. In thatcase, fine particles having a grain diameter of 20 μm or less arepreferably used. Solder or lead-free solder has advantages such as lowcost.

Low power consumption and higher integration can be realized in thesemiconductor device to which the present invention is applied.Therefore, the present invention is effective for a small semiconductordevice to and from which data can be input and output without contact asdescribed in this embodiment mode.

Embodiment Mode 10

This embodiment mode describes an example of application of theabove-described semiconductor device capable of inputting and outputtingdata without contact, which is formed according to the presentinvention, with reference to the drawings. The semiconductor device toand from which data can be input and output without contact is alsoreferred to as an RFID tag, an ID tag, an IC tag, an IC chip, an RF tag,a wireless tag, an electronic tag, or a wireless chip depending on theuses.

A semiconductor device 800 has a function of communicating data withoutcontact, and includes a high-frequency circuit 810, a power supplycircuit 820, a reset circuit 830, a clock generating circuit 840, a datademodulation circuit 850, a data modulation circuit 860, a controlcircuit 870 which controls another circuit, a memory circuit 880, and anantenna 890 (see FIG. 14A). The high-frequency circuit 810 receives asignal from the antenna 890, and outputs a signal, which is receivedfrom the data modulation circuit 860, from the antenna 890. The powersupply circuit 820 generates a power supply potential from a receivedsignal. The reset circuit 830 generates a reset signal. The clockgenerating circuit 840 generates various clock signals based on areceived signal input from the antenna 890. The data demodulationcircuit 850 demodulates a received signal and outputs the demodulatedsignal to the control circuit 870. The data modulation circuit 860modulates a signal received from the control circuit 870. In the controlcircuit 870, a code extraction circuit 910, a code determination circuit920, a CRC determination circuit 930, and an output unit circuit 940 areincluded, for example. Note that the code extraction circuit 910 is acircuit which extracts a plurality of codes included in an instructiontransmitted to the control circuit 870. The code determination circuit920 is a circuit which judges the content of the instruction bycomparing the extracted code with a reference code. The CRCdetermination circuit 930 is a circuit which detects the presence oftransmission errors and the like based on the judged code.

Next, one example of an operation of the above-described semiconductordevice is described. First, a radio signal is received by the antenna890. When the radio signal is transmitted to the power supply circuit820 through the high-frequency circuit 810, the power supply circuit 820generates a high power supply potential (hereinafter referred to asVDD). The VDD is supplied to each circuit in the semiconductor device800. A signal transmitted to the data demodulation circuit 850 throughthe high-frequency circuit 810 is demodulated (hereinafter, such asignal is referred to as a demodulated signal). Moreover, signals passedthrough the reset circuit 830 and the clock generating circuit 840through the high-frequency circuit 810, and the demodulated signal aretransmitted to the control circuit 870. The signal transmitted to thecontrol circuit 870 is analyzed by the code extraction circuit 910, thecode determination circuit 920, the CRC determination circuit 930, andthe like. Then, based on the analyzed signals, information of thesemiconductor device stored in the memory circuit 880 is output. Theoutput information of the semiconductor device is encoded through theoutput unit circuit 940. Furthermore, the encoded information of thesemiconductor device 800 is transmitted by the antenna 890 as a radiosignal through the data modulation circuit 860. Note that a low powersupply potential (hereinafter referred to as VSS) is common in theplurality of circuits included in the semiconductor device 800 and VSScan be GND.

In this manner, data in the semiconductor device can be read bytransmitting a signal to the semiconductor device 800 from acommunication device and by receiving a signal which is transmitted fromthe semiconductor device 800 with the communication device.

The semiconductor device 800 may be either a type where no power supply(battery) is built-in but an electromagnetic wave is used to supply apower supply voltage to each circuit, or a type where both anelectromagnetic wave and a power supply (battery) are used to generate apower supply voltage for each circuit.

Next, an example of usage of a semiconductor device in which data can beinput and output without contact is described. A side surface of amobile terminal which includes a display portion 3210 is provided with acommunication device 3200. A side surface of a product 3220 is providedwith a semiconductor device 3230 (see FIG. 14B). When the communicationdevice 3200 is held up to the semiconductor device 3230 included in theproduct 3220, the display portion 3210 displays information about theproduct, such as its materials, its place of production, inspectionresults for each production step, a history of the distribution process,and a description of the product. Further, when a product 3260 isconveyed by a conveyer belt, the product 3260 can be inspected by usinga communication device 3240 and a semiconductor device 3250 with whichthe product 3260 is provided (see FIG. 14C). By application of asemiconductor device to such a system, acquisition of information can beperformed easily, and high function and high added value can berealized. Further, since a semiconductor device according to the presentinvention can realize lower power consumption and high integration, asemiconductor device provided for a product can be miniaturized.

As described above, a semiconductor device of the present invention hasa very wide range of application, and can be used in electronic devicesin various kinds of fields.

Embodiment Mode 11

According to the present invention, a semiconductor device serving as achip having a processor circuit (hereinafter also referred to as aprocessor chip, a wireless chip, a wireless processor, a wirelessmemory, or a wireless tag) can be formed. The semiconductor device ofthe present invention has a wide range of uses. The semiconductor devicecan be applied to any product of which information such as history isclarified without contact and made use of in production, management, andso on of the product. For example, a semiconductor device of the presentinvention can be provided and used for bills, coins, securities,certificates, bearer bonds, packing containers, books, storage media,personal belongings, vehicles, groceries, garments, health products,daily commodities, chemicals, electronic devices, or the like. Examplesof them are described with reference to FIGS. 11A to 11G.

Bills and coins are currency in the market and include notes which arecirculating as the real money in specific areas (cash vouchers),memorial coins, and the like. The securities refer to checks,certificates, promissory notes, and the like, and can be provided with achip 190 including a processor circuit (see FIG. 11A). The certificatesrefer to driver's licenses, certificates of residence, and the like, andcan be provided with a chip 191 including a processor circuit (see FIG.11B). The personal belongings refer to bags, a pair of glasses, and thelike, and can be provided with a chip 197 including a processor circuit(see FIG. 11C). The bearer bonds refer to stamps, rice coupons, variousgift certificates, and the like. The packing containers refer towrapping paper for food containers and the like, plastic bottles, andthe like, and can be provided with a chip 193 including a processorcircuit (see FIG. 11D). The books refer to hardbacks, paperbacks, andthe like, and can be provided with a chip 194 including a processorcircuit (see FIG. 11E). The storage media refer to DVD software, videotapes, and the like, and can be provided with a chip 195 including aprocessor circuit (see FIG. 11F). The vehicles refer to wheeled vehiclessuch as bicycles, ships, and the like, and can be provided with a chip196 including a processor circuit (see FIG. 11G). The groceries refer tofood goods, drinks, and the like. The garments refer to clothes, shoes,and the like. The health products refer to medical appliances, healthappliances, and the like. The daily commodities refer to furniture,lighting apparatuses, and the like. The chemicals refer to medicaldrugs, agrochemicals, and the like. The electronic devices refer toliquid crystal display devices, EL display devices, television devices(television receivers and flat-screen television receivers), cellularphones, and the like.

Such a semiconductor device can be provided by being attached to thesurface of goods or being embedded in goods. For example, in the case ofa book, the semiconductor device may be embedded in a piece of paper; inthe case of a package made from an organic resin, the semiconductordevice may be embedded in the organic resin.

As described above, the efficiency of an inspection system, a systemused in a rental shop, or the like can be improved by providing thesemiconductor device for packing containers, storage media, personalbelongings, groceries, garments, daily commodities, electronic devices,or the like. Further, the semiconductor device being provided forvehicles can prevent forgery or theft of the vehicles. By implanting thesemiconductor devices in creatures such as animals, identification ofthe individual creature can be easily carried out. For example, byimplanting or attaching the semiconductor device with a sensor in or toa creature such as livestock, its health condition such as a currentbody temperature as well as its birth year, sex, breed, or the like canbe easily managed.

Note that this embodiment mode can be implemented in combination withany of Embodiment Modes 1 to 10, as appropriate.

This application is based on Japanese Patent Application serial No.2007-244821 filed with Japan Patent Office on Sep. 21, 2007, the entirecontents of which are hereby incorporated by reference.

1. A semiconductor device comprising: a substrate having an insulatingsurface; a first transistor having a first semiconductor layer, a firstgate insulating layer and a first gate electrode layer, over thesubstrate having the insulating surface; a first insulating film whichcovers the first transistor; an interlayer insulating layer over thefirst insulating film; a second transistor having a second semiconductorlayer, a second gate insulating layer and a second gate electrode layer,over the interlayer insulating layer; and a second insulating film whichcovers the second transistor, wherein the first semiconductor layer isbonded to the substrate having the insulating surface with a firstinsulating layer, wherein the second semiconductor layer is bonded tothe interlayer insulating layer with a second insulating layer, whereinthe first transistor is an n-channel transistor and the secondtransistor is a p-channel transistor, and wherein the second insulatingfilm has a compressive stress, and a channel formation region of thesecond semiconductor layer is distorted due to the compressive stress ofthe second insulating film.
 2. The semiconductor device according toclaim 1, wherein the first semiconductor layer and the secondsemiconductor layer are overlapped with each other with the interlayerinsulating layer interposed therebetween, and the first transistor andthe second transistor are electrically connected to each other by awiring which is formed in an opening which penetrates the secondinsulating film, the second gate insulating layer, the secondsemiconductor layer, the interlayer insulating layer, the firstinsulating film, and the first gate insulating layer and reaches thefirst semiconductor layer.
 3. The semiconductor device according toclaim 1, wherein crystal plane orientations of surfaces of the firstsemiconductor layer and the second semiconductor layer, which areparallel to the insulating surface, are {110}.
 4. The semiconductordevice according to claim 3, wherein crystal axes of a channel lengthdirection of the first semiconductor layer and the second semiconductorlayer are <110>.
 5. The semiconductor device according to claim 1,wherein a channel formation region of the first semiconductor layer isdistorted due to a stress of the first insulating film.
 6. Thesemiconductor device according to claim 1, wherein the first insulatingfilm and the second insulating film are silicon nitride films or siliconnitride oxide films.
 7. The semiconductor device according to claim 1,wherein the interlayer insulating layer is a silicon oxide film or asilicon oxynitride film.
 8. The semiconductor device according to claim1, wherein the first insulating layer and the second insulating layerare silicon oxide films which are formed by a chemical vapor depositionmethod using an organosilane gas.
 9. The semiconductor device accordingto claim 1, wherein the substrate is a glass substrate.
 10. Thesemiconductor device according to claim 1, wherein each of the firstsemiconductor film and the second semiconductor film is a single-crystalsemiconductor layer.
 11. The semiconductor device according to claim 1,wherein difference in mobility between the first transistor and thesecond transistor is reduced by causing a distortion in the channellength direction of the second semiconductor layer of the secondtransistor.
 12. A semiconductor device comprising: a substrate having aninsulating surface; a first transistor having a first semiconductorlayer, a first gate insulating layer and a first gate electrode layer,over the substrate having the insulating surface; a first insulatingfilm which covers the first transistor; an interlayer insulating layerover the first insulating film; a second transistor having a secondsemiconductor layer, a second gate insulating layer and a second gateelectrode layer, over the interlayer insulating layer; and a secondinsulating film which covers the second transistor, wherein the firstsemiconductor layer is bonded to the substrate having the insulatingsurface with a first insulating layer, wherein the second semiconductorlayer is bonded to the interlayer insulating layer with a secondinsulating layer, wherein the first transistor is a p-channel transistorand the second transistor is an n-channel transistor, and wherein thefirst insulating film has a compressive stress, and a channel formationregion of the first semiconductor layer is distorted due to thecompressive stress of the first insulating film.
 13. The semiconductordevice according to claim 12, wherein crystal plane orientations ofsurfaces of the first semiconductor layer and the second semiconductorlayer, which are parallel to the insulating surface, are {110}.
 14. Thesemiconductor device according to claim 13, wherein crystal axes of achannel length direction of the first semiconductor layer and the secondsemiconductor layer are <110>.
 15. The semiconductor device according toclaim 12, wherein a channel formation region of the second semiconductorlayer is distorted due to a stress of the second insulating film. 16.The semiconductor device according to claim 12, wherein the firstinsulating film and the second insulating film are silicon nitride filmsor silicon nitride oxide films.
 17. The semiconductor device accordingto claim 12, wherein the interlayer insulating layer is a silicon oxidefilm or a silicon oxynitride film.
 18. The semiconductor deviceaccording to claim 12, wherein the first insulating layer and the secondinsulating layer are silicon oxide films which are formed by a chemicalvapor deposition method using an organosilane gas.
 19. The semiconductordevice according to claim 12, wherein the substrate is a glasssubstrate.
 20. The semiconductor device according to claim 12, whereineach of the first semiconductor film and the second semiconductor filmis a single-crystal semiconductor layer.
 21. The semiconductor deviceaccording to claim 12, wherein difference in mobility between the firsttransistor and the second transistor is reduced by causing a distortionin the channel length direction of the second semiconductor layer of thesecond transistor.
 22. A semiconductor device comprising: a substratehaving an insulating surface; a first semiconductor layer over thesubstrate having the insulating surface; a first gate insulating layerover the first semiconductor layer; a first gate electrode layer overthe first gate insulating layer; a first insulating film over the firstinsulating layer and the first gate electrode; an interlayer insulatinglayer over the first insulating film; a second semiconductor layer overthe interlayer insulating layer; a second gate insulating layer over thesecond semiconductor layer; a second gate electrode layer over thesecond gate insulating layer; and a second insulating film over thesecond gate insulating layer and the second gate electrode, wherein thefirst semiconductor layer is bonded to the substrate having theinsulating surface with a first insulating layer, wherein the secondsemiconductor layer is bonded to the interlayer insulating layer with asecond insulating layer, wherein the first semiconductor layer comprisesn-type impurities and the second semiconductor layer comprises p-typeimpurities, and wherein the second insulating film has a compressivestress, and a channel formation region of the second semiconductor layeris distorted due to the compressive stress of the second insulatingfilm.
 23. The semiconductor device according to claim 22, wherein eachof the first semiconductor film and the second semiconductor film is asingle-crystal semiconductor layer.
 24. The semiconductor deviceaccording to claim 22, wherein a first transistor comprises the firstgate electrode layer, the first gate insulating layer and the firstsemiconductor layer, wherein a second transistor comprises the secondgate electrode layer, the second gate insulating layer and the secondsemiconductor layer, and wherein difference in mobility between thefirst transistor and the second transistor is reduced by causing adistortion in the channel length direction of the second semiconductorlayer of the second transistor.
 25. A semiconductor device comprising: asubstrate having an insulating surface; a first semiconductor layer overthe substrate having the insulating surface; a first gate insulatinglayer over the first semiconductor layer; a first gate electrode layerover the first gate insulating layer; a first insulating film over thefirst insulating layer and the first gate electrode; an interlayerinsulating layer over the first insulating film; a second semiconductorlayer over the interlayer insulating layer; a second gate insulatinglayer over the second semiconductor layer; a second gate electrode layerover the second gate insulating layer; and a second insulating film overthe second gate insulating layer and the second gate electrode, whereinthe first semiconductor layer is bonded to the substrate having theinsulating surface with a first insulating layer, wherein the secondsemiconductor layer is bonded to the interlayer insulating layer with asecond insulating layer, wherein the first semiconductor layer comprisesp-type impurities and the second semiconductor layer comprises n-typeimpurities, and wherein the first insulating film has a compressivestress, and a channel formation region of the first semiconductor layeris distorted due to the compressive stress of the first insulating film.26. The semiconductor device according to claim 25, wherein each of thefirst semiconductor film and the second semiconductor film is asingle-crystal semiconductor layer.
 27. The semiconductor deviceaccording to claim 25, wherein a first transistor comprises the firstgate electrode layer, the first gate insulating layer and the firstsemiconductor layer, wherein a second transistor comprises the secondgate electrode layer, the second gate insulating layer and the secondsemiconductor layer, and wherein difference in mobility between thefirst transistor and the second transistor is reduced by causing adistortion in the channel length direction of the second semiconductorlayer of the second transistor.